TP 420 
.L29 
Copy 1 



SiKENGlH OF WOODEN COLUMNS. 



iii<:p()iii' of certain tests 



FULL-SIZE WOODEN MILL-COLUMNS, 



^lADK 1'<)1{ 



Kostoii }laiiiit'ridiiiTi's }1iitiiai Fire Insniiiiice €o. 



UNDKH Tin: DIKKCTION OF 



PKOF GAETANO LANZA, S.B., C.E 



Of the Mjiss^achnsetts In-stitxitc of Tt'chuolouv, 



Col'YKKillTKI) BY THE AUTHOK, ISS 



i.H'^ 



HOS'l'ON: 1882. 



STRENGTH OF WOODEN COLUMNS. 



iii<:i'Oiri' OF ci^:p.tain tests 



FULL-SIZE WOODEN ffllLL-COLUMNS, 



MADi: 1-()1{ 



Boston i^laiiufacturers Mutual Fire Insurance Co. 



UNDER TIIK DIUKCTIOX jOF 



^ PROF. GAETAXO LANZA, S.B., C.E. 

3° 



C,^'"" 



Of the Massachusetts Institute of Technology. 



CoPYKUiirrp:D bi the Authok, 1882. 



BOSTON: 1882. 



TA 



9 Q 



STRENGTH OF WOODEN COLUMNS. 



To THE Boston Manufacturers Mutual 

Fire Insurance Company. 
Gentlemen : — 

Eight or nine months ago, your President, 
Mr. Edward Atkinson requested me to sup- 
erintend some computations on the strength 
of wooden beams, and columns. He desired 
that I should direct what constants, and what 
formulae should be used in the calculations. 
In regard to the beams, although our data are 
untrustworthy, inasmuch as almost all of them 
have been derived from experiments made upon 
very small beams, nevertheless, I caused the 
computations to be made, with such constants 
as my judgment told me were the most reliable., 

In regard to the columns, I reported to him 
nat the experimental data, on which arc based 
the rules for the determination of the strength 
of wooden columns, were so few, and so 
imperfect, that there were no formulae by 
which it would be at all safe to make the de- 
sired computations, and that the only course 
that lay open to him was to send some columns 
to the Watcrtowu arsenal, and have them tested 
on the government testing machine. He, there- 
upon, decided to have the tests made, and 
asked me to take charge of them. 

Of the rules and formulae for the computa- 
tion of the strength of columns the oldest are 
those of Eulor, and, so far from having gone 
out of use, they have been employed at a very 
recent date by prominent French engineers in 
computing a very important construction. 
This theory assumes that it is possible to 
determine a definite ratio of length to diam- 
eter, different for every different material, and 
that all columns the ratio of whose lengths to 
their diameters is less than this number give 
way by direct crushing, whereas those which 
have the ratio of their lengths to their diam- 
eters greater than this number, give way 
wholly by transverse bending. His formulse 
for the strength of such circular columns as 
yield by bending, are as follows: 

For ends fixed in direction p ^^3,1416)^ d> 

16 ^ 1''' 



For rounded ends 



p_(.3.1416)3 d^ 



wood, Weisbach gives for use in Euler's for- 
mulae E = 1,664,000 and crushing strength per 
square inch = 6770. 

Eaton Hodgkinson made a very extensive 
series of tests on columns, especially of cast 
iron, and deduced from these tests certain 
empirical formulae. These tests form, even at 
the present day, the basis of the most used 
formulae for the strength of columns. The 
strength of pillars of the ordinary sizes used 
in practice has been computed by means of 
Hodgkinson's formulae and tabulated by Mr. 
James B. Francis, and we find in his book the 
following rules for the strength of solid cylin- 
drical pillars of cast iron with the ends flat, 
i. e., "finished in planes perpendicular to the 
axis, the weight being uniformly distributed 
on these planes." For pillars whose length 
exceeds thirty times their diameter, he gives 
the formula : 

^3.55 



W = 99,318 



11.7 



for the breaking weight in pounds, where d= 
diameter of column in inches, and l=length in 
feet. 

If, on 'the other hand, the length does not 
exceed thirty times the diameter, he gives for 
the breaking weight the following formula: 



Wc 



where P —breaking weight in pounds, E== 
modulus of elasticity of the material. For 



W + |c 

where W = breaking weight that would be 
derived from the preceding formula ; W'=act- 
ual breaking weight; c = weight which would 
crush the pillar; or c = 109,801 (.7854d2). 

If the pillar has rounded ends, take one- 
third of the above result. 

For wooden pillars of Dantzic oak, take one- 
ninth of the breaking strength of a cast iron 
pillar. 

Mr. Lewis Gordon devised semi-theoretical 
formulae for the strength of columns, which 
were founded on the assumption that they 
gave way by a combination of crushing and 
bending, and which also involved other as- 
sumptions, a part of which were those ordina- 
rily made in regard to the transverse strength 
of beams. The constants used were deter- 
mined in such a way as to make the results 
agree as nearly as possible with Hodgkinson's 
experiments. The formulae devised by Gordon 
himself only refer to cylindrical and hollow 



cylindrical columns. A formula devised by 
the same course of reasoning and also depend- 
ing, for its constants, on Hodgkinson's experi- 
ments, but so arranged as to be applicable to 
any form of section whatever, is given by 
Professor Rankine. For wood it is as follows: 
7200 S 



P = 



1 + 



3000 r''' 
where P = breaking strength in pounds; 

S = sectional area in square inches; 
1 = length in inches; 
r = least radius of gyration in inches. 
Besides the above we have formulae which 
are practically Eankine's formults, with the 
constants changed. One of these is that of 
Mr, C. Shaler Smith as given in Traut wine's 
pocket book, and applicable, as he claims, to 
a square or rectangular column of white or 
yellow pine. It is as follows : 
5000 S 



P=- 



1 + .004 



d2 



where P=breaking weight in pounds; 

S = sectional area in square inches; 
1 = length in inches; 
d = least side of rectangle. 
I have computed by means of these formulae 
the breaking weights of certain oak columns, 
with the following results: 
Length = 14 feet. 



Euler., 



("Flat ends 

1 Rounded ends. 



■"^^'^^"^ 1 Bounded ends '263,615., 



Diameter Diameter 

10 5 inches. 9.5 inches. 

"8f>,214 479,853 

347,147 232,623 

360,164 

191,286 

Francis /Flat ends 420,Oao 312,795 

ijrancis..|j^Qy^^g^ ends 140,000 104,265 

If we use the average of the results obtained 
from the oak columns that I tested at Water- 
town, we should find for the breaking weights 
of the aboYd columns with flat ends, about 
277,000 lbs., and 227,000 lbs. respectively. 

A glance at the above results will show that 
they diflbr very much from each other, and 
the question naturally arises as to the trust- 
worthiness of the experimental data on which 
they are based. 

The constants used in Euler's formulae are 
not deduced from any experiment on the 
breaking of a column. 

Eankine's and Francis's have for experi- 
mental basis, the experiments of Hodgkinson. 
Jle made a very large number of tests of cast- 
iron columns, none of which were as large as 
those Used in practice. On oak columns, ho 
made seventeen experiments on as many col- 



umns, all cut from one good plank of Dantzic 
oak, the largest of which was five feet long and 
two inches square. Of these seventeen only 
seven were used in deducing his formulae. 

It is plain that such data are insufficient 
and cannot furnish uj reliable information as 
to the strength of a column. 

Moreover, we have the following facts, as 
showing the difi"ereuce of behavior of large 
and small specimens under test : An iron rod, 
five inches in diameter, which was tested on 
the government testing machine at the Water- 
town arsenal, broke under a tensile stress of 
only 3G,000 lbs. per square inch, notwithstand- 
ing that it was claimed by the makers to be of 
very superior quality, and if tested in small 
specimens would have borne very much more. 
In the Journal of the Franklin Institute, for 
September, 1880, we find it stated that Professor 
Thurston, from four experiments on large 
beams of yellow pine, obtained as modulus of 
elasticity 1,387,000 pounds per square inch in 
place of 2,078,000, which he had obtained from 
tests made on small beams of the same kind of 
wood. 

Having thus fully defended, as it seems to 
me, the recommendation I made to Mr. Atkin- 
son, I will add, that besides five tests on full 
size yellow pine columns, and about six on 
full size spruce columns made by Colonel Laid- 
ley at the Watertown arsenal, I know of no 
other tests of full size wooden columns except 
a few made by Mr. Ivirkaldy on pine columns 
twenty feet long and thirteen inches square; 
and Trautwine claims that the results of these 
tests agree well with the formula of Mr. C. 
Shaler Smith. Such agreement must, however, 
be confined to those special dimensions, inas- 
much as a square yellow pine column, twelve 
feet long and eight inches square, would, 
according to Mr. Smith's formula, have for its 
breaking strength 140,000 lbs., whereas having 
ac ually broken a yellow pine post of about 
that size, I found for its breaking strength 
375,000 lbs., which shows that Mr. Smith's 
formula does not furnish correct results for all 
sizes. 

Passing now to consider the experiments 
which are to form the subject of my remarks 
I will say that there have thus far been two 
series of tests, the first made in June and the 
second in November, 18S1. 

In the case of the first series it was Mr. At- 
kinson's desire that neither he nor I should 
take any part in the selection, and hence a 



5 



carpenter was directed to furnish ten columns 
suitable for use in a mill. Four of them were 
of yellow pine, four of white oak, and two of 
white-wood. They were all twelve ft. long, all 
were tapered from bottom to top, and all were 
'^ bored, and we supposed at the time that they 
' had a longitudinal hole extending from end 
to end to allow a free circulation of air, and 
hence to prevent checking and dry rot. The 
larger diameters varied from about 10.5 inches 
to 7.75 inches, whereas the smaller varied 
from about 9.3 inches to about 6.4 inches. 

The pine was of very fair quality, and not 
thoroughly seasoned. The oak came almost 
directly from the woods and was very green, 
and also very knotty. 

All the tests in the first series were made by 
compressing the columns directly between 
two parallel plane surfaces, so that these 
columns were all in the condition of flat-ended 
columns, or columns with their ends fixed in 
direction. In all but two cases fracture oc- 
curred near the small end of the tapered 
posts, indicating that the fracture was one 
of direct crushing, and that the breaking 
strength per square inch could be correctly 
found by dividing the breaking load by the 
number of square inches in the section at the 
smaller end. The immediate location of the 
fracture was generally determined by knots, 
whenever there were knots near the small end 
of the post, the knots apparently causing the 
fibres in their vicinity to be curved, instead of 
straight, and hence reducing the effective bear- 
ing area, nevertheless, the fracture near the 
small end occurred in perfectly straight- 
grained posts, as well as in those where there 
were knots. 

Both horizontal and vertical deflections 
were measured in all cases, sometimes only at 
the middle of the posts, and sometimes at 
other points also. The numbers given in the 
tables in the deflection columns, are the hori- 
zontal and vertical distances of given points 
on the columns from fixed datum lines, and 
hence the deflections under any given load 
will be found by subtracting the first of the 
readings from those corresponding to the given 
load, thus, in yellow pine post No. 1, 1st series 
(as shown in the accompanying tables), the 
horizontal middle deflection was 0.09 in. and 
the vertical 0.03 in., when the load was 180,000 
pounds. 

An examination of the tables will show that 
the deflections in this first series of tests re- 
mained always veiy sinall (almost inapprecia- 



ble), until the load had nearly reached the 
breaking strength, and that when the deflec- 
tion began to be of appreciable magnitude it 
was a sign that the column was beginiug to 
fail; also that, except in the two exceptional 
cases above referred to, the deflection was 
quite small even when the post was near 
fracture, showing that the deflection played a 
quite insignificant part, if any, in the break- 
ing of the posts, so Tinsignificant that a little 
crooked grain or a small knot would have 
more influence than the deflection. Indeed, 
in the case of the posts tested at the Water- 
town arsenal by Col. Laidley, the longest of 
which was about 10 diameters in lengih the 
deflection was never measured, so confident 
Avas he of their breaking by direct crushing. 

That columns whose ratio of length to diam- 
eter is much greater, will give way by bend- 
ing, is of course true, but what is the precise 
point at which bending begins to have an 
appreciable influence in the fracture of posts 
with their ends fixed in direction, and whether 
such is the case in any of the ordinary mill 
columns is a question that can only be deter- 
mined by experiment. Now as to the crushing 
strength per square inch we have from this first 
series of tests an average value of 

4300 lbs per square inch for yellow pine. 

3500 " " white oak-. 

3000 " " " " " whitewood. 

and these results will be found to difier very 
considerably from those most commonly given 
in the books. How and why, I will show when 
I speak of the second series of tests. 

As to the two posts that gave way by bend- 
ing, one was yellow pine post No. 2, and in 
this case the failure was evidently caused by 
a large knot near the middle of the length of 
the post with season cracks around it, the 
knot acting like a wedge and widening the 
season cracks, and causing the post to weaken 
and then to bend. At 60,000 pounds there was 
no measurable deflection, neither was there 
any at 120,000 lbs., nor at 150,000. When the 
load became 180,000 lbs. the deflection became 
about 0.02, then a load of 190,000 lbs. was put 
on and left through the dinner hour, and be- 
fore the end of that time the post had failed, 
the season cracks opening and the post bend- 
ing with the knot on the concave side. The 
behavior of this column shows very plainly 
the importance of determining experimentally 
the power of columns to endure a load for a 
long time. Had the load of 190,000 lbs. not 
been left, but the load increased, it is probable 
that the oolamn would have borne a load as 



great as 210,000 pounds, but the 190,000 lbs. 
was already causing permanent injury to the 
fibres near the point of subsequent fracture. 

The other post that failed by deflection was 
white oak post No. 2, which contained about 
thirty knots, the greater part of which were 
very small. There was, however, a very large 
one near the centre, but fracture was appa- 
rently in no wise influenced by the it, but was 
produced by the fact that the hole bored in 
the post for the admission of air was out of 
centre at the middle. The deflection again 
was very small until the load reached nearly 
the limit of strength; thus at 50,000 lbs. it 
was 0.02 in.; at 100,000 it was 0.04 in.; at 
150,000 it was 0.03 in.; at 180,000 it was 0.07 
in.; but when 200,000 lbs. was applied it rose, 
after five minutes, to about 0.7 in., the column 
rapidly failing. On examination it appeared 
that the holes had been in all cases bored from 
the two ends, and that in only one post of this 
series, viz., the smallest whitewood, did they 
meet in the centre; a section subsequently cut 
from yellow pine post No. 2, and shown in the 
figure, exhibits the great eccentricity of these 
holes. That such holes do not fulfil the object 
for which they were intended, viz., the ad- 
mission of a current of aii', is very plain ; and 
also that, in that case, they are sources of 
weakness in the post, and are worse than no 
holes at all. 

In the second series I made an attempt to 
have the holes bored straight, and, for this 
purpose, had them bored in a machine shop 
on a large iron lathe with a pump augur, the 
first series having been bored by hand with a 
screw augur. While the result was a decided 
improvement on the previous boring, inasmuch 
as there was in every case a hole clear through 
the post, nevertheless it was far from being 
such boring as ought to be done if the post is 
to be weakened as little as possible thereby. 
A sectipn cut from post No. 4 yellow pine and 
post No. 1 yellow pine, of the second series, 
and shown in these figures, will show 
some of the worst of this boring. 

I am fully satisfied that the holes can be 
bored straight, and I would therefore recom- 
mend that no post be accepted for building in 
which the hole has been bored from the two 
ends, and that, in the case of those bored clear 
through from one end, all be rejected, where 
the hole at the issuing end is more than | in. 
out of centre. I am not disposed to recom- 
mend the turning the post down parallel to 



the hole, as we should thus have to cut the 
wood across the grain. 

Before going farther I will proceed to con- 
sider in detail the behavior of the remainder 
of the posts of the first series: 

1. White Oak No. 1.— When loaded with 
50,000 lbs. the middle deflection was about 0.02 
in.; with 103,000 lbs. it was about 0.03 in.; 
with 120,000 about 0.04 in. ; with 140,000 about 
0.06 in.; with 160,000 about 0.08 in.; with 
180,000 about 0.13 in. The load. 180,000 lbs., 
remained on for 15 minutes, during which 
time the compression was constantly increas- 
ing, and when 190,000 lbs. was applied the 
dsflection was again measured and found to 
be about 0.33 in. ; the column was then in pro- 
cess of failing. It w^uld probably have failed 
under 180,000 lbs., had sufficient time been 
allowed. 

2. White Oak No, 3. — The deflection un- 
der 50,000 lbs. was 0.02 in. ; under 100,000, 0.07 
in.; under 150,000 about 0.17 in. This load 
remained for 15 minutes, the deflection in- 
creasing all the time, and then the load was 
increased to 160,000 lbs., when failure took 
place. The failure took place at knots near 
the smaller end, bending concave on the side 
of the knots. 

3. White Oak No. 4. — Middle deflection at 
50,000 lbs. was 0.01 in.; at 100,000 about 0.03 
in.; at the same load after 8 minutes it be- 
came 0.12 in.; in 28 minutes 0.23 in., and 
would probably have failed at this load with 
sufficient time, but after 33 minutes the load 
was increased to 110,000, when the column 
failed at knots near the small end. 

4. Yellow Pine No. 1. — This column was 
entirely free from knots, and (I think) also 
from season cracks. It failed under 270,000 
lbs. by the crushing of the fibres at the small 
end. The deflection at 100,000 lbs. was 0.07 
in. ; at 180,000 about 0.09 in. ; at 220,000 it was 
about 0.13 in.; at 260,000 about 0.17 in. ; then 
270,000 was put on and the post yielded rapidly. 

5. Yellow Pine No. 3. — This column failed 
under 200,000 lbs., the fibres crumpling 4 in. 
to 8 in. from the smaller end where there was 
no knot, and also at 32 in. from the smaller 
end in the vicinity of a small knot. There 
was a double flexure produced just at the close 
of the test, but it is ray opinion that the crump- 
ling nearest the small end was the source of 
failure, and that the other was subsequent to 
that. 



6. Yellow Pine No. 4. — This column failed 
undei- a load of 133,000 lbs. at knots near the 
smaller end. 

7. Whitewood Columns. — These gave way 
suddenly by breaking the fibres near the small- 
er end, giving no warning of fracture. 

The details and all the figures of the above 
tests will be found iu the accompanying tables, 
aud the fractures iu the cuts. Yellow pine 
No. 2 and No. 4 arc those that were on exhibi- 
tion in the Arsenal exhibit iu the late fair of 
the Charitable Mechanic Association. 

Passing next to the consideration of the 
second series of tests, I will state that, having 
reported to Mr. Atkinson the results obtained 
from my first set of experiments, and having 
made certain recommendations in regard to a 
continuance of the tests he authorized me to 
carry them on within certain limits of ex- 
pense, according to my own judgment. 

My first step was to order from the carpenter 
four yellow pine and four white oak posts of 
diameters respectively equal to the larger di- 
ameters of the preceding set. I directed that 
these posts should be procured of a length of 
14 feet, and that then a two foot block should 
be cut from the end of each post. I desired 
to compare the crushing strength of the long 
posts with that of two foot blocks cut from 
the same piece of timber. My directions not 
having been strictly followed, I am only able 
to compare average values, and can only say 
that the blocks and posts were of about the 
same quality, and that some of them did come 
from the same pieces of timber as the corres- 
ponding posts. I then took the precautions I 
have already described in regard to the boring 
of the 12-foot columns, and left the two-foot 
blocks without boring. The results of these 
tests give nearly the same values for the crush- 
ing strength per squaae inch of the blocks, and 
of the posts with their ends fixed in 
direction. In the case of yellow pine post No. 
4, i. e., the smallest yellow pine, we find from 
the tables, a breaking strength of 205,000 lbs. ; 
whereas the corresponding block gave way at 
215,000 lbs.— the post had a hole which, at the 
place of failure, reduced the sectional area by 
about three square inches, whereas the block 
wns not bored. Three square inches is 
more than enough to account for the 10,000 
lbs. less strength of the post, and it is thus 
plain that, even in this case, where the post 
deflected 0.28 in. before breaking, and broke 
at the middle, the deflection had no appreci- 
able part in the fracture. 



The crushing strengths per square inch, as 
deduced from these experiments, were as fol- 
lows: 

YELLOW PIXK. 



1st series. 


No.l 





.... 4.097 
3 tiCl 






" 3 

" 4 


:::::::::::::: 


.... 4,706 
.... 4,600 




2d series. 
Blocks. 


No. 1 





17,064 

.... 4.424 
. 4.704 


4,266 — average. 




'• ;{ 

" 4 




.... 4,330 
.... 4,511 




2d serips. 

POblS, 


>'0.1 




17.909 
... 4,657 


4,492 — average. 




" 3 

" 4 




... 4,084 
... 4,o84 




Avrra 


geof all the above 
nsj; strensrth obtsti' 
re post No. 4, sei-so 


13,3-:o 


4,441 = average. 
4,390 


Cru«h 
squa 


efi from 
ned 


5,400 






WHITE 


OAK. 






No. 1 




... 3.006 






•• 2 




.. 3,788 






'• :< 




... 3,753 






'• 4 




.. 3.4o8 




















13,988 


3,497— average. 


2d series. 
Blocks, 


No. ? 




.. 3.132 
.. 3.139 
.. 3,303 






" 3... 








" 4 




















9.574 


3.191=averase. 






WHITE WOOD. 






No.l 

" 2 




.... 3,333 
.... 2,684 










6,017 


3,009 = average. 



This gives us for such yellow pine as was 
used in these tests an average crushing strength 
of about 4400 lbs. per square inch, and for the 
white oak 3150 lbs. per square inch. 

As to the results obtained by other experi- 
menters, we find in the Ordnance Manual the 
following strengths given for 

YELLOW PiXE. llVIonongahela River.. 6,592 

„„„Ne\vYork: 4.601 

Ne-.v Hampshire 6,2<9 Marvland 6.992 

No. Carolina Cpitch).. 8,947 Ma :sachusetts 5.800 

Florida 8,;i50[ " ... 7,292 

North Carolina 7,836| » (pasture) 6.962 

Alabama 8-"-201 Canada 6.000 

Virginia ".86", Connecticut 5,199 

. " 7.089 

47,480 yorth Carolina 6,550 

"~~~ Alabama 5.7-y 

Average ^913 Virginia 6,902 

Oregon.... 6,072 



WHITE OAK, 

New England 6,668 

West New York 6,620 

Ohio 6,258 



James River, Va 6,667 

117,206 
Average 6,511 

Hatfield gives for crushing strengths, yellow 
pine, 9516; white oak, 6063. 

Eankine gives for crushing strengths, yellow 
pine, 5400; American white oak, 6000; English 
oak, 10,000. 

C, Shaler Smith, according to Trautwine, 
gives as the crushing strength of yellow pine, 
5000. 



On the other hand, the following tables, 
which I have the kind permission of Col. 
Laidley to present to you, give the results of 
the tests on wooden posts and blocks that had 
been made at the Watertown arsenal, on the 
government testing machine, prior to these 
tests, and Avill be found given in full in his 
report of 1881: 

YELLOW PINE— VERY STRAIGHT GRAINED, AN1> SEA- 
SONED ABOUT TWENTY YEARS, 



Crushing 

strength per 

sq. in. 



Arse- 


Length 


Form 


Dimension 

of sec- 
tion — ins. 


nal No. 


—ins. 


of section. 


573 


20.4 


Circular 


10.2 diam. 


578 


119.95 


Rectangular 


10.97x11 


579 


119.9 


Rectangular 


10.96x10.96 


582 


20 


Rectangular 


9 X 9 


583 


16 


Rectangular 


8.02X 8.02 


684 




Rectangular 


4x4 


585 


3 


Rectangular 


1.5 x 1.5 


58G 


6 


Rectangular 


3x3 


587 


6 


Rectangular 


3x3 


588 


3 


Rectangular 


1.5 X 1.5 


589 


3 


Rectangular 


1.5 X 1.5 


590 


3 


Rectangular 


1.5 X 1.5 



6,: 

12)88,( 

7,; 



0) <u 

— , a> 
— o 



From some yellow pine of very slow growth 
they obtained the following results: 



591 
592 
593 


14 

17.2 
19.1 


Rectangular 
Rectangular 
Rectangular 


4.6 X 4.6 
4.6 X 4.6 
5.3 X 5.3 


9,947 
10,250 
7,820 

3)28,017 

9,339 


They then tried some very green, and wet. 


691 
692 
714 


180 
180 
180 


Open rect. 
Open rect. 
Open rect. 


16 X13.65 
16.2 X 7 

17 X 8.75 


3,070 
2,795 
3,180 

3)9,045 

3,015 



Hence we have the following average 
values: 

Straight grained and well seasoned ( Arsen'l test). 7,386 
Slow growth, straight grained and well seasoned 

(Arsenal test) 9,339 

Very green and wet (Arsenal test) 3,015 

Such yellow pine as was used in these tests 4,400 

Rodman's results 7,913 

C. Shaler Smith (according to Trautwine) 5,000 

Why these enormous differences? Evidently 
the higher values are obtained from well 
seasoned and straight grained pieces, in other 
Words, the differences are due to differences of 
quality, differences of seasoning, and differ- 
ences of size of the pieces under test, for with 
small pieces we necessarily have less imper- 
fections than with large ones. Moreover, it is 
plain that it is not safe to use as average 
values, the larger values. 

In regard to white oak, the tests that had 
been made at the Watertown Arsenal previous 



to these were two in number, the specimens 
having been seasoning about 15 years, pieces 
12 inches long, and 4x4 inches in section. 
The crushing strengths per square inch were 
respectively 7375 and 7010 pounds. 

Of spruce, they had made quite a number of 
tests, as shown by the following table: 



Arsenal 
numb'r. 


Length 
—inches. 


Form 
of section. 


Dimension 

of sec- 
tion — ins. 


Crushing 

str'gth per 

sq. in. 


565 


24 


Rectangular 


5%x5% 


4,946 


566 


24 


Rectangular 


5%x5-?^ 


4,811 


567 


36 


Rectangular 


5%x5>s 


4,874 


568 


36 


Rectangular 


^'ix5% 


4,500 


569 


60 


Rectangular 


5%xi}'^ 


4,451 


570 


60 


Rectangular 


Si-gXiiX 


4,943 


571 


120 


Rectangular 


5%x5?^ 


3,967 


572 


120 


Rectangular 


5>«X5J^ 


4,908 




6) 


Rectangular 


5%X^% 


5,275 




30 


Rectangular 


5hxoH 


5,372 




15 


Rectangular 


5HxbX 


5,754 


577 


121.2 


Circular 


12.4 diam. 


4,681 



Next, as to the taperii-ig. Since posts of 
these sizes give way in the machine, by direct 
crushing, and not by bending, it necessarily 
follows that tapering a post is a source of 
weakness, and that we only have left the 
strength of the section at the smaller end. 
This will be more apparent when we look at 
the following comparative vie w of the strengths 
of tapered and of cylindrical posts of yellow 
pine; the latter having approximately the 
same diameters as the larger ends of the 
tapered ones. 

COMPARISON OF THE CRUSHING STRENGTHS OF 

TAPERING AND CYLINDRICAL COLUMNS 

OF YELLOW PINE. 



TAPERED COLUMNS. 


CYLINDRICAL COLUMNS. 


Small 

diam't'r 

-ins. 


Large 

diam't'r 

—ins. 


Break 'ng 
strength. 


Diameter Breaking 
inches. strength. 


9.31 

7.58 
6.40 


10.55 • 
8.99 
7.79 


270,000 
200.000 
138.000 


10.45 390.000 
8.96 250,000 
7.70 205,000 



Hence the tapering of a 10.5 inch post so as 
to have a diameter at the small end of 9.31 
inch was done at an expense of 120,000 pounds 
of strength, etc. Hence it is plain that taper- 
ing a column weakens it. 

Moreover, since the wood is first cut in 
rectangular or square logs, it follows that the 
very turning it down to a circular form causes 
a loss of strength. I would, therefore, recom- 
mend that the logs be used in the square form 
in which they are sent to the market, and be 
not weakened by any reduction in size, and that 



if this cannot be done and round columns are 
required, that they be not tapered, but have 
the same diameter throughout. The money- 
saved by avoiding the turning and tapering 
could be much more profitably spent in im- 
proving the boring and the fitting at the ends. 

In the second series of tests the four yellow 
pine blocks, and three of the oak blocks were 
first tested, and then yellow pine posts Xos. 4 
and 3, the results being as already described, 
the details being recorded in the tables. 

I decided next to make the attempt to imi- 
tate in part the conditions under which a post 
is used in practice, convinced, as I am, that, 
in order to prophesy with any certainty what 
will happen in the use of any piece, we must 
make our tests conform to these conditions. 
The first condition of practical usage to which 
I endeavored to conform was the use of an 
eccentric load, or a load whose resultant does 
not act at the centre of the end of the post. 
That this is the case in practice will be very 
evident when we consider the construction of 
an ordinary mill. 

On the first floor we have a column, resting 
on a flat casting, on top of the column rests 
another flat casting, on which stands a pintle 
in the centre and the two adjacent floor beams 
on either side; above the pintle is the flat 
casting which supports the column of the 
second story, on top of which rests another 
flat casting, which in its turn supports another 
pintle in the centre and the two adjacent 
floor beams of the third story on either side. 

Let us consider now, the column of the first 
story. All the load that is brought upon it 
from the stories, above the second, is brought 
through the pintle, and hence would be, if the 
fitting were perfect, applied at the middle; 
on the other hand, if the floor of the second 
Btory is unevenly loaded, one of the floor 
beams resting on the column having a 
heavier load than the other, the two loads 
due to the weight resting on the second story 
floor would be unequal, and hence the re- 
sultant load upon the column is not applied 
at the centre, but at some point outside of 
the centre. 

My first attempt to imitate in a certain way 
this eccentric loading of a column was made 
with yellow pine post Xo. 2. The post rested 
against a flat casting as shown in the cut, 
buck of this casting was placed a rectangular 
bar whose section was 1.36X1.1 in., the bar 
being placed ia a horizontal position, with its 



centre at a depth of 2.33 in. below the central 
diameter of the column, the pressure being 
transmitted from the piston head of the ma- 
chine to this bar, and thence to the column; 
the other end of the column having a full 
bearing at the other end of the machine. 
The pressure being now applied deflection of 
course set in, reaching 0.02 in. only, at 40,000 
lbs., and constantly increasing with increased 
loads; at 100,000 the deflection became 0.1 iu., 
at 150,000 0.15 in., at 200,000 it had already 
become 0.3 in. and now the plate had percep- 
tibly ceased having a full bearing on the 
top of the post. At 250,000 the deflection 
had become 0.45 in., at 260,000 it was 0.5 and 
increased to 0.5S., the column finally giving 
way at 265,000 by opening longitudinal cracks 
near the end loaded eccentrically, and deflect- 
ing upwards. This column had a sectional 
area of 76.7 square inches and, at the average 
value of the crushing strength per square inch 
of the yellow pine, viz., 4400 lbs., the column 
would have borne 337,500 lbs., thus we have a 
loss of strength of about 72,500 lbs. due solely to 
the eccentricity of the load, and as this eccen- 
tricity must undoubtedly take place when the 
column is in place in a mill, it is evident that 
a certain portion of the breaking strength, by 
no means inconsiderable, is to be deducted 
from this cause alone. This loss of strength 
was not at all as great as it would have been 
had the resultant pressure been applied along 
one horizontal line at the centre of the bar, 
the end of the column being, as it were, 
hinged at this line. In that case, theory 
would give us for the loss of strength 174,- 
600 lbs. instead of 72,500. The remainder 
was taken up by the bending movement 
in the plate and in the bar, the action 
being evidently as follows: The eccen- 
tric pressure brought upon the bar an un- 
equally distributed stress which caused the 
resultant to act at a point nearer the centre 
than 2.33 in., then the rigidity of this bar 
prevented the plate from turning around as it 
would about a knife edge, and caused a bend- 
ing in the plate, so that a free bending of the 
end of the column was prevented, and there 
was a considerable bending moment taken 
up by the plate and bar, the pressure being 
thus, more evenly distributed on the column, 
than it would otherwise have been. It follows 
naturally, that the breaking strength would 
vary with the material of which the bar and 
plate were composed. In this case the plate 
was steel and the bar wrought iron. 



lO 



White oak post No. 3 was next tried in a 
similar manner, the eccentricity of the centre 
of the bar being in this case 1.91 in. The de- 
flection set in at 10,000 lbs., and increased rap- 
idly till, when the load had reached 100.000 
lbs., it had become 1.08 in. ; this increased in 
15 minutes to 1.7 in., and the post was then 
rapidly failing. This post had a sectional area 
of 50.92 square inches. At 3200 lbs. per square 
inch this would have borne with a uniformly 
distributed load 162,900 lbs. ; there was thus a 
loss of 62,900 lbs. due to the eccentricity. Had 
the post been free to turn, or had it been rest- 
ing against a knife edge at the centre of the 
bar instead of against the flat surface of the 
bar, theory would give a loss of 106,000 lbs. as 
against 62,900, thus leaving the breaking 
strength of the post 56,900 lbs. 

In both the above cases it is plain that the 
breaking strength was considerably increased 
by the rigidity of the bar and plate. That 
there is a certain action of the same kind in 
practice from the rigidity of the pintle is also 
plain, and that the better fitted, and the larger 
the pintle the more will be the rigidity, and 
hence the greater the breaking strength. Of 
course it would be desirable to approximate as 
nearly as we can to the rigidity furnished by 
the pintle, or by different pintles, with differ- 
ent degrees of perfection in the fitting. 

My attention was next called to the fact 
that the pintles in practice were likely to be a 
source of weakness, and hence I made two 
tests on columns with pintle ends. These 
tests, as well as those on the eccentric loading, 
hardly furnish more than general indications 
and suggestions for a systemactic investiga- 
tion that ought to be carried on in this 
regard. Thus the pintles in both cases 
were iron cylinders 4.35 in. diameter and 
8.7 in. long, their ends being carefully 
turned in a lathe and made parallel to each 
other. 

The two posts tried in this way were, 1st. 
White o.",'s: post No. 2, a very knotty, and poor 
stick. lb remained with neither deflection, 
nor sliding nor rocking, on the pintles until 
the load reached 60,000 lbs., when motion took 
place near one of the pintles. This is shown 
in the right hand pair of columns of figures 
marked deflections, and it indicates the mo- 
tion of the post at a point 1^ feet from its 
south end. This motion was not great, amount- 
ing only to 0.02 in. As the load increased, 
however, this motion rapidly increased, and 
at 180,000 lbs. a very cousiderablo rocking on 



the pintles had already taken place, thus at 
the north end, the post had moved 0.09 in., at 
the south end 0.16 in. vertically and 0.07 in. hor- 
izontallj'', and it also had taken a very consider- 
able deflection. At 190,000 lbs., where it failed, 
the rocking and deflection had both increased 
very considerably. I f the 190,000 be divided by 
the area of the cross section we should obtain 
a breaking strength of only 2400 lbs. per 
square inch, which is far below any oak pre- 
viously tested. This would make it appear 
that the pintles were a source of weakness, 
causing by their rocking a bending of the 
stick, and thus an unequal stress. Whether 
this is so or not, when the pintles are provided 
with perfectly parallel surfaces as they were 
in our case, is a matter for farther experiment 
to determine. The same post was subsequent- 
ly tried with ends fixed in direction and then 
sawed apart, and one-half tested again with 
ends fixed in direction, but I do not feel au- 
thorized to draw any conclusions whatever 
from these latter tests, as the wood had been 
already subjected to severe stress. Neverthe- 
less, the details are given in the table, and 
any one who feels so inclined can draw what- 
ever conclusions ho thinks proper. 

The other post tried with pintle ends was 
a very straight grained stick of yellow pine 
(yellow pine post No. 1), and in this case there 
was hardly any rocking or sliding on the pin- 
tles, and the post was hardly weakened, 
if at all, by the pintle ends, the break- 
ing being evidently eflected by direct crush- 
ing and not by deflection. 

Besides the above described tests two square 
columns of yellow pine were tested. These 
columns were such as were used in the exhi- 
bition building of the Charitable Mechanic 
Association, and are furnished with a yellow 
pine bolster, into which they are mortised. 
These two columns had been sent to the arsenal 
about the middle of last July, and had re- 
mained in a warm room since that time, so 
that they were in a much more advanced stage 
of seasoning than the other columns tested. 

I first tested one of these, marked yellow 
pine post No. 4. It was placed directly in the 
machine without any eccentricity, resting at 
one end on the platform of the machine, and 
at the other on the bolster, such as is used in 
their building. The post was, as shown by 
the table, about 8.4 in. square. When the load 
had reached 20,000 lbs. the bolster began to 
give way, emitting snapping sounds, and con- 
tinuing to do so, and gradually crushing more 



II 



and more as the load increased ; very soon a 
wedge-shaped piece began to split off from one 
side, and the bearing of the post against the 
bolster was therefore on one side. The bolster 
wa^ left in and allowed to become more and 
more broken up until the load reached 120,000 
lbs., when the unequal pressure on the bolster 
caused the post to crack, the bolster itself 
being in the mutilated condition shown in the 
cut. The bolster was then taken out, the 
tenon on the post sawed off, the end of the 
post squared up, and the post itself tested with 
ends fixed in direction; it bore 375,000 lbs. 
pressure before breaking, when it gave way 
by the crushing of the fibres near one end. 
The pressure was then continued simply for 
the sake of marking the fracture more plain- 
ly, and during this continuance the post took 
a double flexure, giving way at the other end 
also and at the middle, the fracture at the 
middle showing both crushing and tearing of 
the fibres. 

The above test shows how very bad a plan 
it is to use wooden bolsters instead of iron 
caps. The crushing strength in this case was 
5400 lbs. per square inch. 

I next tested the other yellow pine square 
post marked No. 5, first with the bolster and 
an eccentricity of loading. The bolster began 
as before to yield at about 20,000 lbs. and it 
was taken out when the load reached 60,000 
lbs., and the tenon sawed off, the end squared 
up and the post itself tested with an eccentric 
load as before, the centre of the bar being 2.07 
in. eccentric. The column yielded at 240,000 
lbs., the behavior of the preceding posts being 
repeated. In almost all the tests the compres- 
sions under the different loads were measured 
with the view of determining the modulus of 
elasticity, or the ratio borne by the load per 
square inch to the compression per inch of 
length produced by that load, only those loads 
being used where equal increments of load 
give equal compressions. 

In the case of the tapering posts, inasmuch 
iS the section varied at different points, I 
u.ied the middle section in computing the 
modulus cf elasticity. By so doing, I obtained 
the following values: 



YKLLOW PINK. 



WHITK OAK. 



No. 1. 



J,88-..2fM Xo. 1. 

i,wi,u;«: 2. 

2.")87,;i47i -.i. 

2,204.. >8.5 4. 



1 ''22 2^ 

1,5 4,38!) 
1,748,817 

4)6,ir,9,415 



On the other hand, in the second series of 
tests there could be no question as to what 
section to use, for they were of the same sec- 
tion throughout, and the following value.s 
were obtained : 



YELLOW PIXK BLOCKS. 



l,(io7,425 
2,113,411 
l,G14,4.-):i 
1,<)00,2.')2 

4)7.f>4r..571 



Average . 



WHITE OAK BLOCKS. 



No. 2 


l,.6o,382 


4.....^....'.... 


1.H>4,9;18 








3):{.r)72,94:{ 


Average ... 


l,19v>.'Jiil 



YKLLOW PIXK COLUMNS. 

No. 3 2,100.882 

4 2,081,3.1 

2)4,251 ,205 



Average 2,1:25,01/2 

We thus have as average values: 

YELLOW PINK. I WIIITK OAK. 



1st series 

2fl series blocks. 
2d series post.s.... 



1,952,0:8, 1st series 1,539.8.34 

1,911,393 2d series blocks. 1,190,981 



2,12J,(>02 

3)5.989.0.53 

l,996,a51 



Average 



Average . 



,yj-,05s; Avera^re . 



As to the discrepancy of the values deduced 
from the blocks and posts of yellow pine, it 
seems to me that it is probably duo to the fact 
that the tests on posts and blocks were made 
in about the same length of time, and hence 
the intervals of time between the successive 
loads were about the same in the posts as in 
the blocks, and the posts may not have had 
suflicient time allowed to assume all the com- 
pression they would otherwise have assumed. 

Now, as to instances of failure of mill 
columns in use, while I have made no 
special effort to ascertain them, I have 
heard of some from various causes; it is 
probable that were the matter fully inves- 
tigated, more would be heard from. In one of 
the cases which have come to my attention 
dry rot was the cause of failure; in some 
others excessive and long continued damp- 
ness ; and in another instance I was informed of 
the case of a burning mill five stories high, in 
which the floors fell in within twenty minutes 
after the alarm was sounded, and the whole 
building was in ruins inside of one hour. My 
informant thinks that the columns in this 
case were loaded nearly up to their breaking 
strength, and that then, a little charring so 
weakened them as to cause sudden failure. 
Without disputing his conclusions, since he 
was an eye witness of the occurrence, it 
seems to me that another cause must also have 
had a part in the transaction. Since the mill 



12 



was five stories in height, whenever the floor 
beams on one side of a vertical series of 
columns burned the set of columns was left in 
the condition of one very long column, and any- 
initial deflection arising from imperfect fit- 
ting, would at once be very much increased 
by the eccentric loading, and the conse- 
quently long and jointed column would 
easily bend and fall. Now we need to 
know, just how far we can go safely in making 
a long column, and then either confine our- 
selves to a smaller number of stories, or else 
put in columns that will bear the greatest 
loads that can come upon them, together with 
their greatest eccentricity, and besides this 
we need to have very careful fitting between 
the cap plates and the pintles, and also, it 
seems to me exceedingly desirable, to know 
by actual test what is the result of just such 
imperfect fitting as we meet with in practice, 
and I believe it to be perfectly possible, by 
means of the power wo have at our command, 
in the government testing machine, to thor- 
oughly investigate this point, and hence to pre- 
scribe such conditions for the fitting as shall 
keep us within safe limits. 

I will noAV proceed to sum up what, as it 
seems to me, are the conclusions that we may 
fairly draw from these experiments, in the 
light of the previous tests made at the arsenal, 
and the recommendations that these conclu- 
sions would lead me to make. 

1. I should recommend that the longitudi- 
nal holes in wooden mill columns be bored 
from one end only, and that all posts be re- 
jected in which the eccentricity at the other 
end is greater than a given small amount as 
three quarters of an inch. This recommenda- 
tion is made in view of the facts that holes 
bored from the two ends are very liable not 
to meet in the middle, and hence not to allow 
a circulation of air, that if the hole becomes 
very eccentric the column is liable to be 
weakened, and also by the presence of two 
holes at the same section. 

2. I should recommend that mill columns 
be not tapered, as the tapering is a source of 
weakness, the loss of strength in one of the 
eases tested amounting to about 120,000 lbs. 

3. I should also recommend that square 
columns be used in mills instead of round 
ones, for the reason that the timber comes to 
the wharf in the form of square logs, and 
when the columns are made round, they are 
cut from the square form, and this cutting 
awiiy cf the wood is a source of weakness. 



4. The strength of a column of hard pine 
or oak, with " flat ends," the load being uni- 
formly distributed over the ends, and of the 
diameters tested, is practically independent of 
the length up to a length of twelve feet (how 
much further can only be decided by further 
experiment), such columns giving way prac- 
tically by direct crushing, the deflection if 
any being as a rule very small and exerting 
no appreciable influence on the breaking 
strength. 

5. The only exceptions to the above are 
found in cases where there is good reason 
for departure from the rule, as in the case of 
very imperfect wood or* of very eccentric 
holes, but even there the influence of the 
deflection in reducing the strength is not 
nearly as great as has been generally sup- 
posed. 

6. No formulae founded on the generally 
received hypothesis, that the deflection exerts 
a very considerable influence on the breaking 
strength of such columns as those referred to 
represent correctly their breaking strength for 
all lengths and diameters. 

7. For such columns as those referred to, 
the most correct rule for determining the 
breaking strength is to multiply the number 
of square inches in the section (the smaller 
section being used in the case of tapering col- 
umns) by the crushing strength per square- 
inch, of the wood. 

8. The crushing strength per square inch 
varies very considerably in specimens of diff- 
erent degrees of seasoning, also in large and 
small specimens. 

9. The average crushing strength of wood 
is much less than has been supposed by many. 
That of some very highly seasoned hard pine 
was found at the arsenal to be 73S6 lbs. For 
some hard pine of very slow growth and very 
highly seasoned an average crushing strength 
Avas found of 9339 lbs. For some very wet 
and green they found a crushing strength of 
3015 lbs. For some yellow pine which had 
been seasoning about three months I found 
5400 lbs. For average crushing strength of 
such posts as I tested, not thoroughly seasoned, 
and not very green I found about 4400 Ibs.i 
wbereas in none of these cases did I obtain a 
greater result than about 4700 pounds. Hence 
it would be entirely unfair to assume a crush- 
ing strength of 8000 lbs. for yellow pine. For 
two specimens of white oak tried at the arse- 
nal and very thoroughly seasoned, an average 
was obtained of about 7150 lbs., whereas for 



13 



such oak as was furnished me, which was very- 
green and very knotty, I obtained an average 
of about 3200 pounds. 

10. I would recommend the use of iron 
caps instead of wooden bolsters, as wood is 
very weak to resist crushing across the grain ; 
and the wooden bolster will fail at a pressure 
far below that which the column is capable of 
resisting, and the unevenness of the pressure 
brought about by the bolster is so great as to 
sometimes crack the column at a pressure far 
below what it would otherwise sustain. 

11. Any cause which operates to distribute 
the pressure on the ends unevenly, or to force its 
resultant out of centre, is a source of weakness, 
and brings about a very considerable deflec- 
tion, which exerts an important influence in 
reducing the breaking strength. 

12. As far as these experiments have gone, it 
appears that such pintles as were used in these 
tests, when the fitting is perfect, exert no in- 
fluence upon the breaking strength of perfect 
and straight grained columns, but that they 
probably are a source of weakness in the case 
of imperfect and knotty wood, and especially 
in cases where there is an incipient deflection. 
Farther experiment is needed, however, to 
answer these questions fully. 

13. I would also recommend that the horizon- 
tal holes connecting the longitudinal holes with 
the outside air be made in the iron cap, and 
not in the wood; this will prevent weakening 
of the post by the hole, and will prevent the 
closing of the hole by change, in moisture and 
other causes. 

I 14. Another conclusion which I think, is 
very evident, is that the crushing strength of 
full size columns cannot be fairly inferred 
from tests made on columns no larger than five 
feet long and two inches on a side. 

While it seems to me that the above conclu- 

1 sions can be drawn with certainty, the tests 
have furnished a large number of suggestions 
as to what ought to be done, and of opinions 

I as to what would probably happen in certain 

( cases of testing, but I should hardly feel will- 
ing to state mere opinions until they are veri- 

' fied or disproved by experiment. Nevertheless 
it seems to me that I have shown the great 
importance of carrying these tests farther, 
and making such a systematic inquiry into 
the strength of wooden mill columns that we 
may be able to predict with certainty what 

i' such columns will bear under all the usual 

I conditions of loading. Such a systematized 
set of tests would neces-sarilv cost more than 



the Boston Manufacturers' Mutual Fire Insur 
ance Company would feel justified in expend- 
ing, but would be only a trifle if taken up by 
two or three of our wealthy mill corporations 
and would far more than repay them, for the 
entire expense would be as nothing compared 
with the falling of a mill. 

In such a set of tests properly carried out 
one should feel his way very carefully, and 
one result would naturally suggest another 
experiment; hence it would be very unwise 
to mark out beforehand the series of tests to 
be made, and not to allow modifications as 
circumstances might require. Nevertheless 
these tests have furnished such a quantity of 
suggestions that I can readily map out, in a 
general way, a series of tests that should be 
undertaken, and then modified as new sugges- 
tions arise. 

1. All the sizes of columns ordinarily used 
in mills should be tested, both in the seasoned, 
and the unseasoned state, and both of oak and 
hard pine; or, rather, such a number of sizes 
should be tested that we may be able, from 
these, to infer with certainty, the strength of 
the remainder. We should thus ascertain 
whether, in any of the sizes used in mills, the 
deflection has any serious influence on the 
breaking strength, or whether such influence 
is confined to ratios of length to diameter 
greater than those used in mills. If the former 
is the case, the amount of influence of dif- 
ferent lengths should be definitely ascertained. 
We could thus make out a table showing what 
are the breaking strengths of flat-ended mill 
columns where the load is uniformly distribu- 
ted over the ends, 'and of such sizes as are 
commonly used. 

2. All the difi'erent forms of pintles in com- 
mon use should be tested to see what is their 
eflect on the breaking strength of the columns, 
and in so doing, we should endeavor to imitate, 
as far as possible, all the imperfections of fit- 
ting used in practice. This, I believe, it is 
perfectly possible to do. 

3. We should ascertain how the strength of 
a column with what, for want of a better term 
might be called rounded or pin ends, difi'ers, 
if at all, from that of a column with ends 
fixed in direction, Hodgkinson claimed that 
the strength in these cases was very much 
decreased, in the longer columns to one-third 
what it was with flat ends. The efi'ect of the 
tests on my mind in this regard is (to say the 
least) to throw a very grave doubt on such a 
conclusion, when the resultant of the load 



H 



passes through the centre of the column, and 
the question ought certainly to be settled. 

4. We should then ascertain the effect of 
using ill fitting pintles and eccentric loads, 
thus trying to imitate, as far as possible, the 
conditions of practice. 

5. We should examine the different kinds 
of wood used for mill Columns, and ascertain 
its crushing strength both before and after it 
has been in use in a mill. 

6. Another series of important experiments 
would be a set of tests to ascertain the effect of a 
long continued operation of loads less than the 
breaking load. These tests could be conven- 
iently made, I believe, at the arsenal, though 
not in the machine; and the very fact of 
a column (1st series, yellow pine, No. 2), 
which broke at 190,000 pounds, acting for an 
hour, and which would probably have borne 
200,000 or 210,000 pounds, if it had been ap- 
plied at once, gives us good reason to suppose 
that, if the loads were left on for a month or a 
year, that a load considerably less than the 
instantaneous breaking load would produce 
rupture of the column, especially when 
changes of load occur. 

Besides the above there are a great many 
other points that would present themselves 
during the course of the tests such as the 
determixiation of the limit of elasticity, if 
such a thing exists; the modulus of elas- 
ticity, etc., etc. Also, it might be desirable to 
test two columns in line with a pintle between 
them. Such information as that described 
(whi^h would however be of immense value 
to the mills, and to constructors generally) 
would require a carefully conducted and sys- 
tematic series of experiments on full size mill 
columns. The cost of such a set of tests is, of 
course, difficult to estimate exactly, and if the 
tests were not carefully planned and made, 
and the results were not carefully watched 
and correctly interpreted, it might involve a 
great deal of expense. But if the tests were 
properly conducted I should estimate the cost 
of a quite extensive series that would furnish 
a large amount of information somewhere in 
the neighborhood of $4000. This is a larger 
sum than an insurance company would feel 
justified in spending on such a matter, but if 
undertaken by two or three mill corporations 
they would not feel the expense, and, when- 
ever a question arose, as to the safety of adding 
weight on their columns, or of putting in new 
columns, they would have some information 
on the subject that could bo depended upon. 



I will say that Mr. Atkinson has authorized 
me to carry these tests a little farther, and 
that I shall therefore touch upon one or two 
of the matters mentioned above, but all that 
I can do, while keeping within such limits of 
expense as he can authorize me to make, will 
be to obtain a few more suggestions which 
will be far from giving us all the information 
on the subject, that we need. I would there- 
fore urge upon our mill corporations the im- 
portance of having such a series of tests made 
while the matter is fresh, and not to wait 
until some disaster calls more forcible atten- 
tion to it. 

I cannot close without a"knowledging spe- 
cially the assistance and suggestions I have 
received from Mr. Hjw;ird, the skilful oper- 
ator of the machine, and also a great many 
suggestions wliich I hava either received 
directly, or have been led to think of, by 
some remarks made casually by other people 
who have taken an interest in these experi- 
ments. 

In conclusion. I desire to emphasize very 
strongly, the great importance of conforming, 
in our testing, to the conditions under which 
the piece under test is used in practice; and 
bearing in mind that tests made under any 
different conditions only furnish us certain 
data, by means of which, with the use of our 
judgment, to determine the behavior of the 
piece in practice; and that just as far as wa 
have fallen short of conforming ths conditions 
of the test to the conditions of practice, just 
so far are our data upon which to form our 
judgment insufficient. 

I will add that the results of these tests 
have already been put into practical use in 
a large and important construction. 

Since the above was written, an opportunity 
presented itself for testing some old columns, 
and Mr. Atkinson having authorized me to 
to spend a little more money, but not at all 
enough to make any one of the investigations 
complete, I have used it to obtain a few more 
facts, which contain, as I believe, a number 
of useful suggestions. 

The old columns were all of oak, and came 
from three different mills, which I will call 
re^jpectively mills Nos. 1, 2, and 3, No. 2 being 
the Pacific Mills at Lawrence. The posts 
that were received from mill No. 1, seven in 
number, had been in service about six and 
half years, and were removed because the] 
were deemed unsuitable. They were all about 
12 leet long, about 6^ inches in diameter 



ihe larger end, and 55 to 6 inches in diameter 
at the smaller end. They were all bored and 
the boring vras excellent, as I was unable to 
find one where there was not a hole clear 
through. The load they had sustained is 
estimated by one of the gentlemen connected 
with the mill at about 10,G0O pounds per 
column, besides the weight of the snow in 
winter. They were provided at the top with 
a maple cap surmounted by an ouk base on 
which rested the next column above, or the 
roof timbers. Of these columns three, viz., 
Nos. 191-i. 1915 and 1916, were tested between 
the platforms of the machine, the ends being 
brought to an even bearing. The remainder, 
viz., Xos. 1917, 1918, 1931 and 1932 had the maple 
cap and oak base iutcrposcd between the column 
and the platforms of the machine, the ends, 
of course, not being brought to au even bear- 
ing. It is also to be observed, that all the 
old columns were painted, the defects being 
thereby partially concealed. The results are 
given iu the tables annexed, and, ly dividing 
the breaking weight by the area of the small- 
est section in each case, we find as crushing 
strengths per square inch the followiug: 



Iso. Lbs. No. 

1914 4'.U- 1917. 

liUo Wo2 1918 . 

1916 -ltteLil!-31 . 

1132, 



Lbs. 

-ZH.S 

3263 

4223 

3.oO 



It is to be observed that No. 1914 was not 
straight ; No. 1915 had but few apparent de- 
fects; No. 1916 was not straight, and had some 
large season cracks, one especially being very 
large ; No. 1917 did not appear to have a great 
many knots, and those where it failed were 
not very large ; No. 1918 was not straight, and, 
furthermore, had its larger end decayed ; Nos. 
1931 and 1932 had a number of small knots, 
but did nut appear to have any very large 
ones. As to deflections induced by the load, 
we see from the tables that this was almost 
inappreciable in the case of the second; in the 
first and third it reached about .75 inches; in 

I the fourth about .4 inches, wliile iu the last 

I three it exceeded one inch very considerably. 

It is to be observed that in only one case does 
the crushing strength per square inch reach 
6000 pounds, and also that, iu the case of the 
last fjur, where the maple caps and oak bases 

I were used, and the ends were not squared up, 

the strength averages l^ss than in the case of 

J the first three. 

I Those columns, ten ia number, that are 

marked as coming from mill No. 2, were taken 

• out of the worsted department of the Pacific 



Mills, at Lawrence, where they are making 
some alterations. Six of these came from the 
first floor of the mill, imd are marked A, B, C, D, 
E and F, respectively, and the remaining four 
were taken out of the second story of the mill 
jind are marked respectively G, II, I and J. 
All were about 14 feet long, the first six 
having each a diameter of about 10.5 inches, 
and the last four of about 9.5 inches. Of the 
first six, the first four were tested simply be- 
tween the platforms of the machine, the ends 
being brought to an even bearing in one case 
only, viz., in the case of D. E and F were 
tested with an iron base plate at one end, and 
an iron cap and pintle at the other, the pintle 
being 19.6 inches long, and having for cross 
s( ction a hollow rectangle 8.45X5 inches out- 
side, and 7.1X3.75 inches indde, the base, cap 
and pintle beiug those that had been used in 
the mill with some one of these columns. The 
crushing strengths per square inch, obtained 
by dividing the breaking strength by the 
area of the section iu each case, arc as follows: 

A 4265, ends not Kqaared. 

B :iSSO, 

C I0S4, 

D 4604, ends squared. 

r 4;;C2, \viili piuLie, 

F 4S:;3. " 

Of these posts A was not straight; C had a 
winding grain, season cracks, and was nut 
straight; C was quite knotty and ax)pear«jd 
shaky near the failure ; D, E and F appeared 
to be tolerably free from defects. 

The posts G, H, I and J were taken from the 
second floor of the mill, and are about 14 feet 
long and 9.5 inches iu diameter. The first 
three were placed simply between the plat- 
forms of the machine, the euds being ia no 
case brought to an even bearing, and the 
fourth, or J, was tested with an iron base- 
plate and pintle at one end, and an iron cap 
and pintle at the other. The results arc 
given iu the tables, and from th^m, if we 
divide the breaking weight in each case by the 
area of the section, we obtain, as crushing 
strengths per square inch, the followiug: 

G 4,881, enda not squared. 

H 3,433, 

1 3,981, 

J 3,266, with pintles. 

I will add that these four posts appeared 
quite defective, having a good many knoti, 
and being more or less bent, and, in tlie case of 
J, the post was gouged out to a de;)th of about 
i of an inch for a length of about 20 inc!ics 
uear the base. I a the case of II , the pjst 



1 6 



towards the end of the test took what, for want 
of a better term, I have described as a triple 
flexure, i.e., it had three points of inflection, 
one of which was in the neighborhood of the 
middle where the deflections were measured. 

All these posts from the Pacific Mills had 
been in service about twenty-five years, and, 
if we assume 50 pounds per square foot as the 
weight on the roof and 60 pounds per square 
foot as the weight on the floor, we should ob- 
tain as the load that had been supported on 
each of the first six from 46,400 to 53.650 
pounds, and^s the load on each of the last four 
from 36,800 to 42,550 pounds. 

From mill No. 3 I had one old oak column, 
of which I know nothing about the time it 
had been in service, nor the load it had borne. 
It was placed simply between the platforms of 
the machine and showed a crushing strength 
of 6147 pounds per square inch. 

The above eighteen are all the old oak col- 
umns that were tested. It will be noticed 
that in two cases we cbtain a strength a .ittle 
over 6000 pounds per square inch, but that n 
no other case does the strength exceed oOOO 
pounds, and that in one case in mill No. 1 when 
the maple caps were used, it fell as low as 2913 
pounds per square inch. 

The next set of posts consisted of two white 
oak posts and one white oak block left un- 
tested lasl November. The smaller of these 
posts, marked iu the tables No. 4, second se- 
ries, was tested squarely in the platforms of 
the machine, the ends being brought to an 
even bearing. It had a crushing strength of 
3219 pounds per square inch. The block left 
untested broke with 4450 pounds per square 
inch. The post was, however, very poor and the 
block very good. Both had been kept in the 
storehouse since last November. The remain- 
ing post of this lot had a diameter of 10.95 
inches and this was a poor stick. It was tested 
with the load eccentric 25 inches, the load be- 
ing applied along a single line by the use of 
the castings shown in the sketch, the rigidity 
due to the bar used in making the eccentric 
tests last November being thus avoided. The 
result was, as would naturally be expected, a 
great reduction of strength, as the post, if 3000 
pounds per square inch were assumed as its 
crushing strength, would have borne 270.480 
pounds, whereas the actual load under which 
failure took place was 170,000 pounds. 

The remaining posts and blocks were of yel- 
low pine furnished by Messrs Stetson & Mose- 



ley, and were each four in number. Nos. 1 
and 2 were square, No. 1 being Savannah tim. 
ber, dock seasoned, and No. 2 Brunswick tim^ 
ber, also dock seasoned. The corresponding 
blocks were of the same kind of timber, but ) 
cannot assert that they were cut from th< 
same piece. In the case of the round 
ones the corresponding blocks were cul 
from the same pieces of timber, and bored. 
One of these columns was 11 feet long, Port 
Eoyal timber, seasoned on the wharf, theothei 
was 12 feet long. Port Eoyal timber, and 
dock seasoned. The first was tested between 
the platforms of the machine, and bore 4254 
pounds per square inch, the deflection before 
fracture being very small; the block which 
was salved from the end of the post bore 489S 
pounds per square inch, the post in this case 
having a great many season cracks. 

The other round jjost was 12 feet long and 
was tested with one end flat, the load being 
centrally applied along a single line, by 
means of the castings shown in the cut. It 
bore 4662 pounds per square inch, while the 
block sawed from its end bore only 3604 
pounds per square inch, the block containing 
a knot where failure took place. The square 
posts were tested, one with the load eccen- 
trically applied along a single line, and the 
otht r with a pintle with the ends not parallel. 
The results are n in the tables, together 

with the crusi^ „ strengths of the corre- 
sponding blocks. 

Perhaps the most important result of this 
set of tests is the fact that these old oak col- 
umns which had been iu use gave crushing 
strengths whose average is far below 6000or 7000 
pounds per square inch, and hence that, while 
such crushing strengths and even higher ones 
can be obtained by means of well seasoned 
and perfect pieces, this would not answer for 
an average crushing strength far such oak as 
has been in these mills. Another matter 
f orthy of attention is the fact that these old 
jak columns Were f oquently very brittle, and 
often split on breaking. I was unable to ob- 
tain any old yellow pine columns. 

The experiments with eccentric loads com- 
bined with a bearing along a single line, thus 
avoiding the rigidity of the bar used in the 
other case, showed, as was to be expected, a 
much greater reduction of strength. The ill 
fitting obtained in those posts from mill No. 1 
where the maple caps were used appears to 
cause a loss of strength, but ia the cases of 



1 



I 



the pintles and eccentric loads wc need a large 
number of tests, aud thoso made can only 
serve as special cases. They furnish us but 
little indication in the case of the pintles, and 
still continue to exhibit a large reduction of 
strength in the case of the eccentric loads, 
and a greater reduction the less the rigidity. 

In concluding I can only reiterate what 
I have already said, in regard to the im- 
portance to our mill corporations of having 
a thorough investigation made of these 
matters involving complete series of tests, ia 
which the conditions of practice are approxi- 
mated to as nearly as possible, and I would 
urge the importance of the same kind of in- 
vestigation to those railroad companies that 
use wooden bridges. If formulse could thus 
be obtained for certain cases we should be 
very fortunate, but I look rather for the making 
Df tables, such as I described on page 13 of 
this report, and certainly if formulae could be 
obtained we should expect to find different ones 
for every different mode of fixing the ends. 

Before closing, I must state that I have re- 
cently had some correspondence with Mr. C. 
Shaler Smith, and that I have been requested 



by him to state that the formula given for yel- 
low pine columns iu Truutwine's hand book 
as Mr. Smith's formula, was intended, as I 
understand from his letter, to meet the case of 
such ill fitting joints aud other imperfections 
as occur in practice, and not for perfectly even 
bearings. I will also add that Col. Laidley, of 
the VVatertowu arsenal, is now carrying on a 
set of tests of a large number of white and yel-, 
low pine columns, all tested between the plat- 
forms of the machine with even bearings. 
This series of tests cannot fail to furnish some 
very valuable information, and it would be 
very desirable if it could be followed up by 
other extensive scries of tests such as I have 
already mentioned. 

Eespectfully submitted, 

Gaetaxo Lanza. 
Boston, June 1, 1882. 

This report formed the subject of two com- 
munications, by the author, to the Society of 
Arts, of the Massachusetts Institute of Tech- 
nology; one on December 8, 1881, and the 
other on May 11, 1882, aud of a paper read 
before the American Society of Mechanical 
Eugiueers on April 21, 1882. 



iS 



TA.BLES OF TESTS. 



FIRST SERIES. 



ITellow Pine, No. 1. 

Total length 12 feet 0.15 inches. 

Gauged " 130 inches. 

Good post free from knots. 

Weight 320 pounds. 



Diameter of larger end 10.55 inches. 

" " middle 10.65 '• 

" " smaller end 9.31 " 

" " core 1.67 " 

Maximum sectional area 85.22 square inches 

Minimum " " 65.0 '* " 




i 

"2-42 


li 


ii 

o 






Deflkction. 










a. 


b. 


c. 


Remarks 


Hor. 


Ver. 


Hor. 


Ver. 


Hor. 


Ver. 


m 


5 000 


.8182 
.8150 
.8055 
.796'] 
.7876 
.7782 
.7692 
.7005 
.7506 
.7420 
.7330 
.7330 
.8102 
.7240 

.715:) 

.7200 
.7095 
.8110 
.8116 
.7012 
.0920 
.6820 
.6740 
.6645 
.6552 
.6455 
.6360 
.6262 
.6160 
.6150 
.8080 
.8086 
.6124 
.6035 
r.nor. 




.57 


1.11 


.50 


1.05 


.43 


.99 




10,000 


.0032 
.0127 
.0216 
.0306 
.0400 
.0490 
.0577 
.0676 
.0762 
.0852 
.0352 
.0020 
.0942 
.1032 
.0982 
.1087 
.0072 
.0066 
.1170 
.1262 
.1352 
.1442 
.1537 
.1630 
.1727 
.1822 
.1920 
.2022 
.2032 
.0102 
.0096 
.2058 
.2147 
.2156 
.2252 
.2352 
.2462 
.2547 
.2732 
.2992 
















Ants appear. 


30,000 
40,000 
50,000 
60,000 
70,000 
80,000 








































j^H 














'i^l 














-^^1 


.55 


1.11 


.45 


1.04 


.38 


.98 


1 


100,000 
100,000 
5,000 
110,000 
120,00D 
108,100 
120,000 
5,000 
5,000 
130,000 
140,000 
150,000 
160,000 
170,000 
180,100 
190,000 
200,000 
210,000 
220,000 
220,000 
5,000 
5,000 
220,003 
230,000 
230 000 


.54 


1.10 


.44 


1.04 


.36 


.98 


























1 


^^1 


.52 


1.10 


.44 


1.04 


.36 


,93 


/Rested 15 hours. ^| 
(Load on in morning. 


.54 


1.10 


.43 


1.03 


.36 


.97 







































































y^^ 










:::::::::::: ...;;:;;;:;;i 


!J^| 


.51 


1.09 


.41 


1.02 


.34 


.90 


■ 








: 






















.50 


1.08 


.40 


1.01 


.31 


.95 








































































5 minutes' rest. 


240000 sosfi 1 














250,000 
260,000 
260,000 
270,000 
270,000 
270,000 


.5830 
.5720 
.5635 
.5450 
.5190 
















.47 


1.03 


.35 


.96 


.28 


.91 































5 minutes' rest. 

7 minutes' rest, then failed rapidly. 















Failed at smaller end by the fibres crumpling 1 inch to 8 inches from end. Horizontal deflections show 
column convex on side opposite heart. 

Deflections marked c were measured at the middle, those marked b at a distance of 12 inches ftom th« 
middle, and those marked a at a distance of 24 inches from the middle, both towards the smaller end. 



19 



Yollow t»iiio. Xo. 2, 




Yellow Pine, Xo. 3. 




A'ellow Pine, Xo. 2. 

Total length ;2 feet 0.2 inches. 

Gauged length 13J 

Weight of post 235 pounds. 

Diameter of larger end 10.07 iuches. 

" middle 9.71 

" smaller end 8.30 " 

" *' core 1.7J " 

Ma.ximum .sectional ar u 7.7 b^nare inches. 

Miuinmm " " ol.9 '• " 



5,000 
10,000 ' 

20,0^-0 ; 

30,(X)0 
40,000 i 
50,000 : 

co,ooj : 

fiO.OOO 
70,0.X) 
81,000 
90,000 

100,000 

110,003 
120,003 
120,00-J 

i:iO,ooo I 

140,00i1 I 

1.50, 03 

150,000 ! 

160.003 i 

170,000 

180,000 

180,000 

190,000 

190,000 

190.000 



li 



.&502 
.8446 
.8322 
.8200 
.8065 
.79.3.5 
.7805 
.7792 
.7670 
.7533 
.7450 

.72C0 

.7122 
.6982 
.6960 
.(i830 
.6690 
.6-540 
.'Jolo 
.6375 
.6215 
.6070 
.6032 
.5880 
.5750 



Middle | 
Deflection j 
Readings. \ 



nor. 



Ver. 



.94 



1.52 



oa56 

0180 

0302 
j .0437 

.0-567 
i .0697 
j .0710 
! .0S32 
I .0972 

j .1102 |. 

I i„<o i I ! (Season crack 

I .1-4- I ; ; 1 .>,^^„«^ ,..i^t 



.94 



1.52 



After resting. 



.1.380 
.1520 
.1-542 
.1672 
.1812 
.19.57 
.1987 
.2127 
.2287 
.2132 
.2470 
.2622 
.2752 



.94 I 1.52 I 



j !94'" 


........... 










: .95 


1.50 






1 






opened wider. 



5 minutes rest. 



3 minutes' rest. 



3 minutes' rest. 



8 minn'ps' re<:t. 
Uitim'testreugth 



The load 190,000 lbs. was maintained on t'lis post one 
hour. Yielding began and continued from tlie first 
application, slowly at first, but increasiu'.^ i;i rapidity 
toward.*" the close of the experiment. The b^-havior 
of the column confirming our observation of other 
posts, that a load which at first is sii><tained without 
apparent permanent injury mav be snfHcient to finally 
cripole the column. The post failed at a largo knot in 
the middle. 

Post sawed apart after fracture. Core bored nut of 
centre about 1?:^ inch eccentric, on opposite sides from 
llLlhir« ttC knot. 



Yellow Pine, Xo. 3. 

Total length 12 feet 0.13 inches. 

GauKed " V.0 

Weight 211 pounds. 

Diameter uf larger end 8.99 inches. 

" middle 8.88 

*' " smaller end 7.54 " 

" " core ..1.7 " 

Maximum sec:ional area 61.2 square inches. 

Minimum " " 42.5 " " 



s applied, 
ounds. 

e reading, 
nches. 


.2 ,- 
as 

s 


Middle 
Def.ection 
rtcadings. 


Remarks. 


3 !5 


Ilor. 


ver. 




5,000 ' .7976 




1.40 


1.93 




10.000 ■ .79. JO 


.(•O-W 
.015(5 
.0276 
.0396 
.0514 
.0521 
.0643 
.0760 
.0881 
.1013 
.1141 
.1141 
.1-273 
.IJ.iO 
.1521 
.1663 




20,00iJ i .7820 









30,1X10 .7703 
40,000 .7-580 















50,000 .7462 
50 OIH) : 74 5 


1.42 


1.94 


2 minutes' rest 


60^000 : .733 i 








70.0)0 : . 216 








80,000 1 .7095 
90 I (01 i .696') 














100,0<X> j .6835 
100,1X10 • .6832 


1.42 


1.94 




110.003 1 .6756 








120,00!) ! .6.57') 








1.30.0O3 : .6455 
140,000 1 .'Wl'> 


1.43 


1.95 


Crack heard. 


140.0)' .6.305 
140,000 .6300 
1.50,' KIO 1 .6172 


.1671 
.1676 
.18 '4 






1 . miniite.s' rest. 
4 minutes' rest. 






1.50.003 .6160 
1.50.t)i) ) .61.5) 


.1816 
.1823 
.1951 

.18.30 

.2111 
.•2-241 
.•2374 
.•2->ll 
.2624 
.811 
.3046 




2'2 minutes' rest. 


160,003 .60'2.5 

i30,oco r .r.vir. 


' 


Rt'sred 1-'. hours. 
/ Load on in morn- 
l iug. 


160 003 


.-865 
-5735 
.5602 
.5431 
.5.351 
.5165 
.4930 




170 0(Kj 


... . 






l8;),ot)) 









19 1,00 ) 
190,003 


1.44 






•200,003 
•200,000 
200,000 








.3 minutes' re.st. 






(6 min. res' then 
1 failed rapidly. 













Failed by fibres crumplin:^ 4 in. to 8 in. from smaller 
end, obliquely around post; also fibres crumpled 32 in. 
from smaller end in vicinitv tf small knot. 



20 



Ycllotv Pine, Xo. 1. 

Total length 12 feet 0.2 inches. 

Gauqred " 130 

Sectional area minimum 33 square 

" " maximum 43. G " " 



"Weljht In pound?) ir>4 

Diameter of larger end. 7.79 inches. 

" middle 7.8 

*' " smaller end 6.4 " 

" " core... 1.67 " 




i 


n 

J5 


d 

o 

II 

rs 

8 




Beflkctiox 


IlEADIXO.S. 




RKiTAnKS. 




a2 


a. 


b. 


c. 

- 




§ 


Ilor. 


Ver. 


Ilor. 


Ver. 


Ilur. 


Ver. 




T) 000 


.6612 
.(;d22 

.<;60j 

.63iM5 
.659(] 
.62)0 
.6590 
.603-) 
.<).>S..) 
.5SS0 
.5-^70 
.Oj.2 
..-.72-) 
.5712 
.5780 
.6310 

.5(i(;2 

.530) 
.6')15 
.5350 
.5342 
.53,2 
.030! 
.5102 
.630 ; 
.5030 
.504) 
.6310 
.G31<o 
.4880 
.6512 
.4716 
.4702 
.6506 
.6516 
.4552 
.4526 
.4520 
.6496 
.6512 




2.03 


2.59 


1.89 1 


2.44 


1.S4 


2.40 


Slight cracking sound. 

Sustained 5 minutes. 

After 5 minutes. Rested 15 
The load running down to 

r 

5 minutes' rest. 
1.5 minutes' rest. 

5 minutes' rest. 

4 minutes' rest. 

5 minutes' rest. 

5 minutes' rest. 

5 minutes' rest. 
10 iiiiuutes' rest. 

5 minutes' rest. 
"Ultimate strength. 




10,000 
5,0:10 


.0090 
.0007 
.0246 
.0016 
.0412 
.0022 
.0577 
.00:!2 
.0732 
.0742 
.0040 
•0387 
.0900 
.0i32 
.0102 
.0950 
.1107 
.0097 
.1262 
.1270 
.1270 
.010(5 
.1420 
.0106 
.1502 
.1372 
.0102 
.0096 
.1732 
.0100 
.1S96 
.1910 
.0106 
.0096 
.2060 
.2083 
.2092 
.0116 
,0100 




:!:;"":;;;':::.::-.::: :..::.: :: : v; 


J 


20,000 
5,000 
31,000 


2.03 * 


2.57 


1.38 j 


'li^ 


1.^32 


2.39 


- M 


1 




^ 


5,000 
40,000 
5,00 » 








k.03 


2.58 


1.H6 1 


2.41 


1.82 


2.40 




50,000 
50,000 
5 00J 






















C0,0 
60,000 
52,000 
5.000 
6 ),000 
70,000 


2.02 

""iW 

2.02 


2.58 

""Ziio" 
2.5S 


1.88 1 

"i'.si"' 

1.87 


2.45 

"i'.'i'y" 

2.4 4 


1.82 

""i.ii" 

1.82 


2.10 
2.4J 


hours. 
52,000 lbs. 










5,000 










81,000 
80,000 
80,000 
5,000 
90,000 
5,000 
100,0; 10 
100,000 


2.00 


2.60 


1.85 1 


2.16 


1.80 


2.42 


^^ 






^^^1 


2.02 


2..X8 


l.h8 [ 


2.45 


182 


2.40 


m 








2.00 


2.62 


1.85 1 


2.47 


l.«0 


2.43 


■ 


5,00) 
5 000 


^ 




:::::::::::! :::;;:;:::: 
















^^^1 


110,000 
5,000 

120,00 » 

120,000 
5,000 
5,000 

130,000 

i.;o,ooo 

130,000 
5,000 
5,000 

138,000 












^^^H 








1 






^^^H 






■ 






^^^1 






] 






^^^^1 






i 






^^^^1 






::::::::::::t::::::::::j;::::::::::; 





^^^H 








^^^H 


1.92 


2.66 


1.80 


•/.5i 


1.75 


2.47 


m 


2.00 


2.61 


1.86 1 


2 47 


1..,) 


2.42 


m 









Failed at knots about 4 ins. from the end. The fibres crumpling outside of the gauged length. 
Deflections marked c were measured at the middle, those marked b at a distance of 12 inches troin the 
middle, and those marked a at a distance of 24 inches from the middle, both towards the smaller end- 



21 



TT^aito Oali, T:o. 1. 

Total length 12 feet 0.17 inches. 

Caused " 130 iuchen. 

Weight 393 pounds. 

Diameter of larger end 11.01 inches. 



Diameter of middle 10.15 

" " smaller end 9.15 " 

" " core 1.67 

Maximum sectional area 93. square Inches. 

Minimum " " 63..: 




"7. 


!i 


li 

5 H 




Dkflkctiox. 








c,2 


a. 


b. i 


RKIT.ARK'. 


1 i 1 


iror. Vcr. 


Ilor. 


Vcr. Ilor. i Ver. 




5,0-0 
1 W)M 
" ) 01 • 


.7703 

.7;.o 

.713-.- 
.7 5-31 
.72J-. 
.7)03 
.7fl7!l 
.6955 
.6^93 
•7i;:j3 
.678) 
.7iM0 

.cr,i;3 

.7.130 
.653 ) 
.76!5 
.6362 
.613) 
.6112 
.7013 
.7625 
.6193 
.6152 
.6):,'5 
.5970 
.5813 
.5775 
.5753 
.51.^5 
.5536 

..5ro 

.5302 

.52 ;o 

..501.5 
.4982 
.4703 
.44!)0 
.4075 
.3^543 
.3Tw 


"Vobvj" 
.o;i5 

.0340 
.0175 

.0,5:0 

.0321 
.0745 
.0^,32 
.0370 
.0123 
.03 i3 
.1051 
.0373 
.1233 
.0335 
.13! J 
.1370 
.13->S 
.0133 
.0175 
.1510 
.15(3 
.1095 
.1730 
.18:4 
.1925 
.1950 
.2115 
.2101 
.2330 
.2.3't3 
.2400 
.2•3^5 
.2713 
.29-10 
.3210 
.3025 
.4103 
.4635 


.73 1.40 




1.30 .07 1.26 








, 




31,0J5 

-1 1,0) ) 

5),0J-) 

5 013 






1 1 












.77 j 1.38 


.73 


1.29 .68 


1.24 




C),0K) 
C -.,001 

■),0'>:) 
71,030 

5 010 




















Rn<;talnf»d 1 hnnr 






1 









1 










SI 000 




■ 




5,03) 
91003 




1 j 






1 1 




5,030 
101,000 

101,0-33 
101 Oil 


""^6""\""i:w" 


........... 


■"l"27"' 


1 ^ 


5 minutes' rest. 








10 minutes' rest 


5 0)3 




' 






5.000 
110,0^0 
110,001 
12),Oi3 
lJ),fK)3 
133,030 
l:] t,013 




























.75 1 1 35 1 .72 


1.26 


.68 


1.22 


5 minutes' rest. 










5 minutes' rest. 
10 minutes' rest. 

5 minutes' rest, 

5 minutes' rest. 
10 minutes' rest. 

5 minutes' rest. 

5 minutes' rest. 
15 minutes' rest. 
Ultimate strength. 










i;3 010 








14),0.0 
U 1,0 10 
151.033 


.75 1 1.31 1 .70 


1.-4 I .67 


1.20 








153,a03 
151.0;X) 














10,001 
1G>,001 


.74 1 1.33 j ,70 1 1.23 | .65 


1.18 


173,00 ) 





18»,0>3 
181,003 


.75 1 1.26 1 .71 


1.17 1 .65 1 1.13 


1'' 1,003 






191,033 


.83 1 i.m 


.77 


.97 


.70 


.93 



Fa'.le.i at knots 12 in. and 15 in. from smaller end. After the post had yielded under 131,000 lbs. and contin- 
ue 1 to f-iil under that load, pressure was suddenly applied, increasing the loal to 135,033 lb.s.,the column yielding 
all the time. 



Wbile Oak, Xo. 2. 



TVbitc Oak. No. 3. 




White Oal£, No. 2. 

Total length 12 feet 0.2 inches. 

Gauged " lob " 

Weight 325 pounds. 

Diameter of larger end 10.23 inches. 

" middle 9.4 

" " smaller end S.Z7 " 

" " core 1.G7 

Maximum sectional area 70.8 square inches. 

Minimum sectional area r2.8 ,, 



Kiddle 
Dcflec'.ion 
r.eadinrs. 



bD 




a 


c 




o . 






o^ 


^^ 






?- = 

3*"* 


en 


B'^ 




o 


o 


U 


.8532 




.8470 


.0002 


.8350 


.0182 


.8232 


.0300 


.Mlf) 


.0410 


.7!);).-, 


.0537 


.787.J 


.0600 


.7750 


.0782 


.7622 


.0010 


.7490 


.10:2 


.7:r,fi 


.1176 


.7348 


.1188 


.7332 


.1200 


.7202 


.1330 


.7d6j 


.14^6 


.or.o 


.1602 


.G77'l 


.1756 


.032!) 


.1906 


.0600 


.1932 


.G4fO 


.2072 


.'276 


.22:6 


.0110 


.2412 


.0015 


.2517 


.r,702 


.2770 


.54H5 


.3047 


.51! 2 


.34_0 


. 17. 


.37 2 


.3770 


.57( 2 



Ilor. 



Ver. 



1.02 1.55 



,0 I 



.98""|"""].' 




2 mTnu'c-;' rrpf. 
6iuiuuu,s' resi. 



3 minutes' rest. 

3 minutes' rest. 
! 3 niiiurcs' res'. 



.46 I l.M 5 i.jinutes" k si. 
1 111 1. uli.stri-n.Lrth. 



Column failed bv dof.ef^tion rt middle, foliowin-T .'ir- 
parcnlly the direction Ci' bendin;^ I'lat \'.>i'. siiclc" l.arl 
(iri'^inally before it was turned into a ol'min, fux ; 
crumpled in vicinity of knots. Sawed apart fCrrr tc t 
at middle, heart at centrf^. Toro h^red 1 i.'. c-'i^on- 
tric at middle of post. The post brnt coucavu 0:1 side 
with the core. 



Oak, Ko. 3. 

Total length 12 feet 0.2 inches. 

Gauged " 130 

Weight of post 2SD pounds. 

Diameter of larger t nd 9.05 inches. 

•' " middle 8.75 " 

" " smaller cud ,.7.55 " 

" *' core 1.07 " 

Maximum sectional area 02,1 square inches. 

Minimum " " -12.6 " " 



i 


1 




fl 





Middle 
Deflection 
r^eadlngs. 


Rkmarks. 

11 


3 


Ilor. 


Ver. 


• 


5,000 


.7932 
.',8.5 
.7085 

!73^0 
.7192 
.VI J 
.7170 

.V 03 
.083-) 

.60^2 
.0485 
.0205 
.(.212 
.0000 

.r,8;6 
.re i 

.5:1 ) 




1.44 


1.92 




10,000 


.006/ 

.0247 

.0407 
.05. 1 
.07-,J 

.0702 
.09-7 
.1097 

.ri, 1 

.14:7 
.1(U 

.1 ;. J 

.18 i 

.20.7 

.2310 

'4i 

AU7 




Z'J; 00 
3J,000 


j 




'10,000 






50,000 
50,000 


].44 1 1.90 




50,000 
(10,000 




about 8 miu. rest. 


70,000 


■"I 




8 1,000 






DO.0^10 
100,1 00 
100,000 


""]."o""j""l.'.S9'" 




llO.OiiO 






120,000 
130.000 

1 ;o,oo ) 






1 ',0,000 1 ."o-:j 
iio.ooo j .47.2 
r,o,cco i .4:0-1 
r.),c oi .3:c5 
100,000 1 


I \ 


1.83 


about 5 min. rest 
lOmin.rest. 
15 min. rest. 

Ultim'testrengih. 



railed rt knots about 24 inches from smalkr end 
bending concave on the side of the knots. 



23 



Oali, >•©. 4. 




Oak, No. :. 

Total length 12 fee: 0.2 inches. 

Gauged length 130 inches. 

Gauging rod screwed to post. 

Three 24 inch sections A, B and C laid oT and round 
headed screws pat in po3t gauging the compression in 
these sections with Vernier callipers. 

Horizontal and vcrllcaL gauglngs to the nearest 
1.100 inches taken at the points a,b, c, d,and c, 12 inches 
apart, c being at the middle of t'.ie length of the post. 



and a and b being toward the smaller end. 

Weigh: in pounds 215. 

Distance of heart from centre large end 1.21 in. about 
" " " " sin^lleaa 0.S3 inches. 

Diameter of larger end 3.06 " 

" middle T.79 " 

" " smaller cud C.G3 " 

" " core 1.C7 ', 

Xinimum sectional area 32 square inches. 

Maximum " " 88 



i 
ll 


j3 


Is 

o 


< 

1 




o 

1 




DEFLECTION'S 


— EEADIXGS IX IXCHES. 


! 


TvEMAKKS 


a. 


b. 


c. ; 


d. 


1 

e. 1 

1 


1" 


Hor. 


Ver. 


Hor. 


Ver. 


Hor. 


Ver. 


Hor. 


Ver. 


Hor.' 


Ve- 




5.000 ! .4382! 


.201 
.196 
.198 
.l!r2 
.198 
.189 


.194 
.192 
.194 
.189 
.194 
.18.5 


.181 
.178 
.180 
.175 


2.00 


2.71 


,.«., 


2.G6 


1.92 

1.S--2 


2.-.7 
2..37 


1.82 


2.47 


1.83 


2.40 




5.000 


.4o<W .0016 
.40o() -0 9ii 
















20,000 
5,000 
30,000 












1.90 
1.92 
1.92 
1.91 
1.92 
1.91 
1.92 


•2..56 
2..57 
2.-,6 
2.57 
2.36 
2.57 
•i..56 













.4370 
.:teD2 
.■!:;7J 
.3700 
.43(52 
.3-500 
.4365 
.3300 
.4332 
.310) 
AS-Ai 
.2870 
.4330 
.2636 
.4'>!)0 


.0012 
.0490 
.0012 
.0682 
.(1 20 
.0882 
.(XH7 
.1082 
.0030 
.1277 






























.SOOO 
40,000 











































5 000 


.197 


.195 |.181 




















so'ooo 

5,000 






















i 


— 


















C0,00<) 
5,000 

70,00) 
5,00) 

8->,000 














1.93 
1.93" 


2.56 
■■2.'.55" 










.197 


.193 |.181 






















.0032 
.1512 
.0052 
.1746 
.0092 
.0060 
.2016 
.20(.-2 
.2117 
.2202 
.2266 
.23<">2 
.2.336 
.2370 
.a302 
.0-^7 








• 


























1.94 
1.92 
1.96 


2.54 










5 000 


.195 


.192 i.lSO 


' 














90,000 


















5,000 





















5,000 ! .4.^"2 




















;";;;:': 




5 min rest. 


IOO.OjO 


.23;;6 

.2320 
.'220.5 
.2180 
.211(5 
.-080 
.20-J5 
.2012 
.40») 














1.99 


2. .2 











]00,0 








1*),0'« 






2.13 


2.62 


2.10 


2.56 


2.03 


2.30 


1.94 


2.40 


1.90 


2.:v. 


8 min. rtst. 


lOO.tiOO 


i 








103,00) 




















21 min. rest. 


10.t,00) 

la'i.ooj 


1 . 


1 2---a 


2.59 


2.18 


Z03 


"■' 


|2.46 










23 min. r- st. 
32 mill, rf'^t. 


10it,000 


























5,001 


i 

1 


! 


2.0(> 
2.05 


2.(:8 
2.69 


2 02 
2.02 


2.63 
2.63 


1.96 
1.95 


2.34 
2.54 












5,000 1 .41(i5 












• 5,a'0 .418-) ■ .0197 
5,000 .4196 .0186 


.185 


1 .191 j .178 










JO niin rest 
















■ 










no.noo .1775 






2.92 


2..T2 


2.83 


1 ?'>7 


2.64 


1 ??3 













Sustained 110,000 lbs. momentarily, but yielded Immediately, and failed at the knot shown by sketch. 



24 

TS'liitewoocl, No. 1. 



;>:^:wmimm!''m-itAmm^m'»-w f ^"- ' iMmm 



Tl^hitewood, No. 2. 



TTIiitewood, No. 1. 

To'a.1 lenctti 12 feet 0.2 inches. 

G-J3cd •' t :::o " 

V.'cljlit Impounds. 

Diameter of larger end 0.C5 inches. 

" " middle O.Cl " 

" " smaller end.. C.<G " 

" " core 1.G7 " 

irariimum sectional area TC.9 square inches. 

I.II::lnau:n " " C4. " " 

Gtlck does not contain the heart. 



i 


o 


h 

t- -J 

a 


Middle 
Deflection 
r.eadincs. 


Kemakks. 




I-Ior. 


Yer. 




5,0-^0 


.831(5 

.t)_-0 
.810) 
.7050 
.7800 
.77'J5 
.7G-U5 
.7492 
.7402 
.7310 
.7190 
.70-10 
.G3S5 
.(J376 
.G722 
.G370 
.0536 
.0530 
.G 90 
.G240 
.G226 
.C030 
.5395 
.5370 
.5325 
.5705 
.5/72 
.5312 
.5420 




.90 1..5.S 




2J,G0J 
S0,030 


.OUG.i 

.02ia 

.03GJ 
.0516 
.<.52l 
.0670 
.0324 
.0824 
.0976 
.1126 
.1 76 
.1431 
.1440 
.15!)4 
.1746 
.1760 
.17C6 
.11^26 
.2076 
.2090 
.2256 
.2421 
.2146 
.2191 

.2701 
.2896 




4 ),COJ 
4,),00:) 


i.(/2 1 \.u 


2 minutes' rest. 


CJ.OOO 
1 0,000 
C0,C03 


i.^ri iir 


2 minutes' rest. 


7.),G30 
€.),00;) 






9),G;.0 

rj.),coa 
1 ;>),ooj 

] 10,000 

32),o:;o 


iV(i4"| i.'vi" 


2 minutes' rest. 


i:),o 






n:),o:_;0 




3Ja uuiiULi-a' le.jt. 


i:j,coo 

1 !0,C0O 


i.. 1 1 i.Gu 




I" 0,000 






13 ),000 
130,000 
1 0,000 


i.oi j i.iij 


2*2 minutes' rc^t 






i:o,ooo 
r,o,o;;o 


1 


7.U minutes' reft. 


170,000 

130,000 


i'.i r 


i'.to" 


Ultimate strength. 



Sustained 180,000 lbs. about 5 minutes, yielding all the 
time, then failed suddenly at the smaller end, the Hbrcs 
bcndian and cruc^plins. 



lyiiitewood. No. 2. 

Total length 11 feet 11.63 inches. 

Cauged '" l;.o *' 

V/cight ICOpou k'<-. 

Dian,eter ui largtrtnd 7.V-incucs. 

'■middle 7.0 

" " fimnlicr tiids ('.8 " 

" *' ov e 1.G7 " 

Maximum stc^i ./Ua,i a. ^u -'A.H bquare inches 

I.J. nimuni " " -9.8 " " 

Post cut out of large siicK. ; aoes not contain the 

heart. 



■g 



o 



o.-^OO 


.81P2 


10,000 


.7u;o 


20,000 


.7070 


20,0 


.7600 


5,000 


.8125 


30,C00 


.7380 


30,000 


.7376 


40,000 


.7095 


50,000 


.0810 


60,000 


.6530 


60,000 


.f!530 


7O.C00 


.G235 


80,000 


.5860 


80,000 


.5650 



.0193 
.0492 
.0502 
.0037 
.0782 
.0786 
.10()7 
.1352 
.1632 
.1G32 
.1927 
.2302 

.2512 



Middle 
Deflection 
r.cadings. 



Ilor. 



Ter. 



2.; 5 'I A! 



.15 2.-.d 



"2y.d""j""2.'45' 
'2!l2"T"2;^' 



2 minutes' rest. 
2 minutes' rest. 

2 minutes' rest. 



2 minutes' rest, 
Ujiim'te strensvth 



Tailed by f.hrcs crumhllng at rmallcr end. 



Yellow Pine Post, No. 




The above cut exhibits the eccentricity of the holes 
iu Pluc Tost ls"o. 2. 



lEc? ">>-!> «r:rcTT^-5=». 



Yellow Pine Post >'o. I. j Diameter of rore l.riOfnolies. 

Weight ;5-:2 pounds, j i^ectiomil i.rea ClT-.^rj. ii,s. 

Length l-14iiu<hfs. ; Counterweight at middle -150 lbs. 

I>ia^el^T'{^side)ZZZZZZZZZZM.4oinches. j l^ested with pintle ends. 







Dkflkctions. 



l^i ft. from X. end. 1 



I'j ft. from y. end. | 



Rkmakks. 



Iforizon. j Vi-rfcal. i Horizon, j Vertical. . Horizon, j Vertical, l 



5,000 
10,000 
20,000 
30,01X3 
40,000 
50,000 
60,000 
70,000 
80,000 
90.000 
100,000 
110,000 
liO.OOO 
130,000 
140,000 
150,000 
IHO.OOO 
170,000 
ISO.OOO 
100,000 
200,000 
210,000 
220,000 
2:10.000 
240.000 
250.000 
2f)0,000 
270.(300 
280,000 
290.000 
300,000 
310,000 
320,000 
330,000 
330,000 
340,000 
3-50,000 
360.000 
370,000 
380,000 
3<)0,000 
390.000 
390.000 









13 

































(3 

























-.01 
—.01 
—.01 
—.01 
—.01 
—.01 
—.01 
—.01 
+.07 















































—.01 
—.01 
— 01 
—.01 
-.01 
-.01 
—.03 
-.03 
-.03 
-.0? 
-.01 
-.01 
-.01 
—.05 
—.05 
—.05 
-.05 
-.05 
—.00 
-.05 




































—.01 
—.01 
-.01 
—.02 
-.02 
-.02 
—.02 
—.02 
—.02 
—.02 
—.02 
—.03 
—.03 
—.03 
-.03 
-.03 
— .0! 
-.03 
-.03 
—.03 
—.03 
-.0} 
-.03 


.12 

















6 










—.01 
—.01 
—.01 
-.01 
—.01 
—.01 
—.01 
—.01 
—.01 
-.01 
—.01 

— !oi 

—.02 
— 02 
-.02 
—.02 
— .nt 
—.01 
-.01 
— .'>5 
—.05 
—.05 
—.05 
—.05 
—.05 
.04 




























































































































































—.01 





-.01 





-.01 





—.01 





—.01 





—J'l 





—.01 





-.01 





—.01 





-.01 





—.01 





-.01 





—.02 





—.02 





—.02 





-.02 


—.02 


+.03 



10 minutes' rest. 

Ult. str'gth=4i3o7 lbs. per sq. in- 



Post failed by deflecting horizontally, opening season crack.s and crumpling the fibrea. 



26 



Yellow Pine Post, No. 2. 

Weight 320 pounds. 

Total length 143.27 inches. 

Gauged length 140 " 

Diameter (outside) 9.92 inches. 

Diameter of core 1.53 " 

Sectional area 75.45 sq. inches. 



Counterweight at middle 150 pounds. 

Thickness of steel plate 1.5 inches. 

Thickness of iron rod l.l inches. 

Width of iron rod 1.36 inches. 

Loaded eccentrically as shown by the cut. 
Eccentric'.ty 2>i inches. 




•1. 


8 


1 




Dkflkctions. 






n 


Centre. 


2'i feet from centre, 
near eccentric end. 


Remarks. 


Horizon. 


Vertical. 


Horizon. 


Vertical. 




5,000 



.0010 
.0045 
.0087 
.0131 
.0170 









2 






S 



S 

.02 
.03 
.01 
.05 


.06 
.06 
.07 
.08 
.08 


.08 
.08 









.02 
.04 


.05 
.08 
.10 
.10 
.10 



.11 

.12 
.13 
.14 
.1) 

.16 
.17 
.20 
.21 

.25 



.25 
.27 
.30 
.31 
.32 


.31 
.35 
.38 
.42 
.50 

















.02 

.03 

.04 

.05 


.06 

.06 

.07 

.08 

.08 



.08 

j'6 

.10 


.10 
.10 
.10 
.10 
.10 





:S; 



.05 

.08 

.10 

.10 

.10 


■}l 

.13 
.14 
.15 

.16 
.17 
.20 
.21 
..30 


.33 ' 
.36 

;S 

.41 


.40 
.42 
.45 

.50 
.58 




10,000 
20,000 






.. 




30,000 
40.000 






50,000 






5,000 







fiO.OOO 


.6261 
.0250 
.02'0 
.0«2 
.0375 


^^J 


70,000 





^M 


80,000 






90,000 
100,000 




■ 


5,000 


■"o 


- ^H 


110,000 


.0412 
.0150 
.0400 
.0525 
.0562 




120.000 




'^^^ 


130,000 






140,000 






150,000 






5.000 







160,000 


.059-) 
.0630 
.0665 
.06' 6 

.0727 




170,000 
180,000 




' 


190,000 






200,000 




riK inch steel plate leaves bear- 
1 ing at top of post. 


.",000 





210 000 


.0748 
.0775 
.0770 
.0800 
.0795 




2:0.000 


.. 




220,000 






230,000 




.10 
.10 

.10 
.10 
.10 
.10 
.10 


^m 


230,000 






5.000 







2 tO.OOO 






210,000 






5 minutes' rest. 


2')0,000 






260,000 


j 




2-0.000 


! 




265,000 


' 


Ultimate strength. 



I 



The maximum load was sustained momentarily, yielding rapidly taking place. It is very probable that had 
the load, 260,000 lbs., been carried a few minutes longer, that failure would have taken place under that load. 
Post failed by opening longitudinal cracks at end loaded, eccentrically deflecting at the time upwards. 



Yellow Pino Post. No. n. 




Veliow Pine Post, No. 3. 

Weight 2 1!) pounds. 

Total lenglii..„ 143.2 inches. 

Gauged Iciigll; KO " 

Diameter (outside) 8.90 inches. 

Diuinetei- of core 1.04 " 

Sectionul area 01.2 sq. inches. 

Counterweighted at niiddie ,:•....; .12(; pounds. 




Yellow Pine Post, No. 4. 

Weight ISO pounds 

Total length .' 14;:.7 inc|ies. 

Ganged length 110 

Piainetei*(ouiside.) 7.7 Indies. 

Diameter of core 1.33 " 

Sectional area 44.72 s(i. inches. 



C'KXTRK 

DKh'i.KcTiox; 



o.oin ) ; ' 

lO.dt)) .()0T, i 

2-VJO) .)ViH ,0 

•Si.),yj) .l)2I!l : 

4(»,J0) .'W7.1 

50, W) .04SO : 

5,0>)) 

c^,<n) .0-J-.2 

70,'VI) .OfiSO 

H),ajJ .1)791 

90,00) , .0900 n 

1M,M) I Am) —.02 

r>,')0) ' 1)010 

ll'j,r)0) I .lllj —.02 : 

J2),0(J) .1220 . — .Oi ■ 

13),0J) .1:{:W —.02 | 

111,00) : .1440 —.0.5 ! 

loO.ouj i .i.')')0 — .0;i I 

r>,o;i.) • tjoii) , 

IfiJ.OOJ Ai.-yJ 1:2 —.0(1 I 

]GJ,yO') ' .l(i(i9 02 — .00 I 

170,009 .177« o:; —.07 1 

i.S'j.ooo .1-8-) 01 : -.07 ! 

l-i0,000 .1895 .0") : —.07 ! ") minutes" rest. 

190,000! .2000 ' .00 I —.07 I 

299,00.)' .21:0 ; .07 ' —.09 

1:99,009 , .2140 07 ■ -.09 i -> minuter,' rest. 

r),00)' (KXiO . ! 

210,'MJ9 .22(x) .0^ I —.10 ' 

219,0'J)| .22(i8 i .08 I —.10 1 o minutes" rest. 

229,009! .2380 .09 | —.10 I 

2;j'),000 ! .2-)00 ! .09 I —.10 

230,009 1 .2-148 .10 1 —.11 ."> minutes' re.st. 

210.009: .'2tm 10 I —.11 

210,00)! .279H 10 —.13 

2.-)0.009! .2920 , .10 | -.13 • 5 minutes' rest. 

250.000' ' '.fUlt.str'th== 405.5 

• .; ( lbs. per sq. in. 

Rapid failure looii jilace after sustaining the maxi- 
mum load ab )ut 8 minutes, crumpling the fibres at a 
distance of 3 10 4 feet liom end. 

Post sawfd apart after tlie test, showing the holes 
bored out of ceiilru at Ihe middle o!" the i/(jst. 






.5,000 
10,000 
20,01 !0 
3i),0(M 
40,00 ) 
.50.01- ) 

;5,00) 
f.0,009 
70.00i) 
SO.DlU 
!M),!!IK) 

]o;),(;oo 
;5,o;)0 



llor. I Yer. 



(*9H5 

nil 

lOfio 
1423 



110,000 .1.500 



120,000 

1:50,00;) 

140,000 

1.50,000 

.5,000 



.171.5 . 
.187.5 . 
.2022 . 
.2192 . 

.1 



1 GO ,000 I .2350 



100 000 
170,000 
170,000 
180.000 
180,000 
190,000 
190.000 
200,000 
200,000 
205.000 
205 000 
205,000 



:384 .... 
.2540 .... 
.2509 .... 
.2724 .... 
.2770 .... 
.2938 .... 
.3000.... 
.3184 .... 
.3300 .... 
.;M18 .... 
.3590 .... 






—.07 





—.08 





-.09 





-.10 











-.10 





-.11 





-.12 


.0 


—.13 





—.14 





-.1.5 





-.17 





-.18 





-.20 










-.24 





-.28 



Counter weigt"d 
at middle with 
. 88 lbs. 



;> minutes' rest. 

5 minutes' rest. 

.5 minutes' rest. 

5 minutes' rest. 

o minutes' rest. 

.5 minutes' rest. 
Ult. strength. 



After .sustaining the maximum load 8 minutes fail- 
ure occurred very rapidly by dellecting downward and 
sideways. Splitting and crumpling of the fibres taking 
place at the middle of the post. After the test the 
post was sawed apart near the middle, showing the 

I core not in the centre, and the holes which were bored 

i from each end did not coincide. 



28 



Yellow Pine Post, No. 5. 

Weight 298 pounds. 

Length 150.8 inches. 

Sectional area.... 03.1 square inch. 

Loaded eccentrically at end with wooden bolster. 



Same plate and rod used as with yellow pine post 
No. 2. 

Eccentricity (to middle of wrought iron bar 2.07 ins 

Counter weighted,,, ,.,,,.,. ,....i:0 pounds 




i 

M 


Dkfi.kctioxs. 




II 
P 




Middle. 


2':a ft, irom middle. 
Horizon, f- Vertical. 


Rkmabks 


3 


Horizon. Vertical. 




5.000 
10,000 
20,000 
30,000 
40,000 
60,000 
60,000 






+.04 
.13 
.22 



















Q 

+.04 
.15 
.32 






!t;:l9 
9.39 
9.34 
9.22 
9.00 


Vield still continuing. 



Wooden bolster removed and ends carefully squared. Tested with same eccentricity 2.07 as before. 
Arrangements of plate the sarne as on yellow pine post No. 2. 



i 


h 

u 

r 


1 




Dkflectioxs. 




■ 


IS 


Centre. 


2'i feet from centre. 


Hem ARKS ^^1 


Horizon. 


Vertical. 


Horizon. 


Vertical. 


^H! 


5,000 
10,000 
20,000 
30,000 
40,000 
50,000 
60,000 
70,000 
80,000 
90,000 
100,000 

5,000 



.0010 
.0039 
.0072 
.0110 
.0149 
.0190 
.0228 
.0265 
.030 1 
.0340 
















+.03 
.03 
.03 
.03 
.03 


.03 
.03 
.03 
.03 
.05 


.05 
.05 
.05 
.05 
.05 


.05 
.05 
.07 







, +.03 
.06 
.07 
.10 
.12 
.14 
.16 
.18 


.20 
.24 
.26 
.30 
.33 



.37 
.41 
.46 
.54 
.60 
.03 
.(iS 
,74 
.83 
,95 


S 






.03 
.03 
.03 


.03 
.03 
.03 
.03 
.05 


.05 
.05 
.05 
.05 
.05 


.05 
M 
.07 








+.03 
.06 
.07 
.10 
.12 
.15 
.18 
.20 


.24 
.26 
.31 

.;« 

.40 


.45 
..50 
.56 
.62 
.68 
.10 
.SO 

1.12 
1.20 
.25 


. 




.; 




J 




,'^ai 




M 




^ 




. 















110,000 
120,000 
130,000 
140,000 
150,000 
5,000 
160,000 
170,000 
180,000 
190 000 


.0380 
,0412 
.0447 
.0475 
.0500 


^ 


■ 





















.0511 
.0520 
.0520 
.0520 
.a511 
















200,000 
5,000 
210,000 
220,000 
230,000 
240,000 
240,000 
5,000 






—.0010 
















i 








1.00 
,11 




Ultimate strength. 











Post failed by opening longitudinal cracks at the end loaded eccentrically. 



Yellow Pine Post and Bolnier No. 4. 

Weight 248 pounds. 

Gauged length 



.140 inch c 



Sectional area 68.3 square inches. 

Bearing of post on bulster not a good one. 
Pust concave on upper side couuter weighted 150 lbs. 




i 


c 






'^i 


":: n 


•2:^ 


Ckntbe 


'y. — ■ 


srs 


si 


Dkflkctions. . 
























^S, 1 


1^ 






^3 


a-" 


B 






- o 




3 1 


Horizon. 


Vertical. 


f:^ 


• 5.000 















10,000 


.ooas 








, 


20,000 


.0010 


-.03 


+.i>2 




30,000 


.0090 


-.01 


+.03 . 




40.000 


.0202 


-.m 


+x:.i 




50,000 


.0.'i20 







7/i2 


o.OOO 










60,tH)0 


.fM50 






/. ■} 


G.1.000 


.a>2s 


— .'Jo 






70,000 


.a>9.-) 


—.If) 


--.f'l 




To ,000 


.0S78 


—.05 




(. "> 


80,000 


.0760 


—.()-) 


-.01 




.^.-,,000 , 


.as40 


— .!)■» 






90,000 


.0900 





—.03 


(..5 


95.000 


.0960 





■ ~-'l^ 1 




100,000 


.1025 





: -.0-:) 1 




iaj,ooo 

120.000 








6.S0 



Kf.makks. 



Snappinr; sounds proceed from bolster. 
Post rcachc:> n full bearing on bolster 



End with bolster has moved over laterally }i inch 
owing to yielding of bolster. 



30 



Maximum load on the po.st while the holster was in wt<5 lonn^ ik<. i-^^ ,u 
this load a crack at end A was enlarged giving evidence thaT tuT^ l!f VC^'^^^^^- P?'' ^"^'^^^^ J°ch. Under 
in the meantime had become thoroughly Sked^wfnl to th."^^^^^^^^ Z^^ mcrcctsed. The bolster 

bolster from impertect workmanship; slight cracks foTloled the lh'^f^c.^fl^' "^"^'"i" ^^ "'^ ^"^'i «" the 
compression The cracks Rradually developed as the loads wSeincrLt^^^^^ ^'^^^'^ ^^ 20,000 lbs. 

v^?llfaS%S^airst^^^^^^ sciuared. Total length 

m lower end by crumpling the fibres and cau^di.ff siV^h^ H^flf'tl '''^ V, 5'^iP"^" ^^il':^ about 15 inches 



irom lower end by crumpling the fibres and causing slVhr (\^ftZ7in.i,\ '-^ H"^'» ^^i^'fi about 15 inches 



Yellow I»ine Klock, T^To. 1. 

Total length 24.125inches. 

Gauged length 18 inches. 

^'^"^«ter 10.46inches. 

Sectional area 85.9 sq. inches' 

^^'-■■■: G2 pounds. 

ihis b.oci was ia wet condition, tlie juice running 
out when drivins the screw.s for measuring points. 




Loads ap- 

plieci. 

Pounds. 



5,000 

10,000 

50,000 
5,000 

80,000 
100,000 
5,000 
120,000 
150,000 
5.000 
170,000 
200,000 

5,000 
210,000 
220,000 
230,000 
210,000 
250,000 

5.000 
260,000 
270,000 
280,000 
290,000 
300,000 

5,000 
310,000 
320,000 
330.000 
340,000 
350,000 

5,000 
360,000 
370,000 

380,000 



Compres- 
sion. 
Inches. 



.0002 
.0052 



.0090 
.0111 



.01.37 
.0179 



.0200 
.02.38 



Perma- 
nent sets. 



Rkmarks. 



.0250 
.0205 
.0276 
.02,S8 
.0300 



.0315 
.0",29 
.0341 
.0355 
.0380 



.o:«5 

.0398 
.0412 
.0129 
.0446 



.0468 
.0510 

.0620 



Rested 1 hour. 



JUlt. strength = 4124 
I, lbs. j)er sq. in. 



Failure by crumpling fibres and opening longitndi 
nal crack. Failed rapidly jis soon a.s the luaximun 
strain was reached. 



Length. 



Yellow Piae Block, No. 2. 



Gauged length "il I^^h^^" 

Diameter...^: «ov °^S^^" 

Sectional area ■.'.■.■: b'i'->-i^!^ \^^^^^' 

Weight '^--^ ??• inches. 

" o2 Dounds. 



wm 


^E 


^S 


S^^B 


Loads ap 

plied. 

Pounds. 


- Compres- 
sion. 
Inches. 


Perma- 
nent sets. 


Eemakks. 

1 


5,000 
10,000 
20,000 

3;),ooo 

5,000 

40,000 

50,000 

5,000 

60,000 

70,000 

80,000 

90,000 

100,000 

5,000 

110,000 

120,000 

130,000 





.0006 












•I 





1 


.0014 
.00.10 













.00.30 
.00.38 
.0019 
.0057 
.0068 





















iiiii 












140,000 






150,000 






5,000 







160,000 


.0128 
.0140 i 
.0150 1 
.0161 1 
.0171 I 

^ois5""'| 

.0195 ! 
.0206 
.0219 
.0230 , 




170,000 






180,000 






190,<i00 






200,0'0 






.\ooo 

210,000 i 
220,000 







230,0fiD 






240.000 






250,00) 1 






5,000 : 


.0007 




260,000 i 
270.000 


lili 




280,000 1 






290,000 
300,00-1 






5,000 


.0009 




310,000 ; 


.0320 '. 

.08:!6 

.03'i0 

.03s8 

.0130 




320,000 ' 
330,00) ■ 






3(0.O'-»0 






350.000 1 






5,00) '. 


.IX)31 I 




360,000 


.0498 ! 




3:58,000 . 




1 


run. strength -=4704 
I lbs. per sq. inch. 


'i 



J-oads applied gradually. When the maximum 
strain was nearly reached, the fibres failed rapidly 
crnniplmg -u the middle and also at the end. in the 
vicinity of knots, the greatest disturbance of the fibres 
taking place at the niiddk- of the block. 



31 



Yellow Pine Bloek, Xo. 3. 

Total length 24'8 inches. 

Diameter 8.1)1 inches. 

Seclional area 62.3) sq. inches. 

Gauged length 18 inches 

Weight 41 pounds. 




Yellow Pine Eloeb, Xo. 4. 

Lpngh 24 inch. 

Ciauged Length 18inclu 

Diameter 7.70 inch. 

Sectional Area 47. (Ki inch. 

Weight 29 lbs. 



Loads ap- 
plied. 
Pounds. 


Compres- 
sion. 
Inches. 


Pornia- 
ntnt sets. 


Kemarks. 


5,000 




.0007 
.OMO 

.Oo-,i 
.0070 
.0089 




This block it is sup- 
posed came off the 
cud of Post Xo. 3. 


10 0:t<) 




20 Oik) 




3i).0»X) 






4).noo 






oH.OOO 






o.OOO 







OO.OOO 


.0105 
.0121 
,0139 
.01.54 
.0170 




7').000 







soooo 






00(X)0 






l.;0.0(X) 
5 0O0 


.'(KKJ5 




1 10,0(X) 


.01>«4 
.0200 
.0 16 
.02:n 
.0247 




120,<KX) 






1:50,000 
140,000 







loO.lXK) 






5000 


.0010 




160 OiX) 


.0260 
.0-277 
.0290 
.0308 
.03-22 

V6339' 

.0:«6 
.0373 
.0400 
.04-23 
.0443 
.0450 
.04)0 
.0460 
.0465 
.0467 




170,000 






180.000 






ino,o<X) 






200,000 

5,000 

210.000 






.0024 




220.000 






230 000 






•^ 10 000 






2)0.000 






2.T<),000 




After omins.' rest. 
After 10 mins.' rest. 
After 15 mins." rest. 

After 5 mins.' rest. 
(Ultimate strength 
\ =4330 lbs. per sq. in 


2-50.000 
2oO,0(X) 




2*50 .<X10 




270,000 




270,000 
270,000 










Fibres crumpled at the ends. 

Lines of fracture followed in directions at 45° to axig 
of block extending from the ends, to 4 ins. from the 
ends. The middle parts of each end 3 ins. diameter 
were unsupported; the compression platforms of the 
testing machine ha%'ing holes of that diameter. 

Also one end of the block was concave, taking a bear- 
ing from the outer diameter 2'2 inches wide. Failure 
began gradually, and after sustaining the maximum 
load about 8 minutes, failure took place rapidly. 

Knots in the vicinity of the fractures may have influ- 
enced the manner and location of failure. 




Loads ap- 
plied. 
Pounds. 


Compres- 
sion, 
inches. 


Perma- 
nent sets. 


Rkmarks, 


5,000 
10,000 
20.000 






.0007 
.0<V2.5 
.0048 
.0067 

'.7)085" 

.0105 
.01-26 
.01 15 
.0166 







30,000 






40 000 






50.000 






5,000 
6 ',000 


,0005 




70,000 






80 000 




- 


91000 






100 000 






5,000 


,0004 




110.000 






120 000 






130 000 






140 'JOO 







150,000 
5,000 






« 




160.000 


,0290 
.on 2 
.03.-59 
.0.361 
.0390 
.0405 
.0421 




170.000 






180,000 
190,000 
200 000 







:;:::::::::::::::: 








200,000 
200.000 




After 3 min. rest. 






200.000 







Rested over night, the packings of the machin- 
allowing the load to fall to 6000 lbs. While under 
strain of 200,000 lbs., cracks opened about a knot at the 
middle of the block. Maintaining this load about 13 
minutes did not further weaken the block. The load 
was then gradually increased to 215,000 lbs. This load 
was sustained 30 minutes, and then the block failed 
rapidly, by opening longitudinal cracks. 

Ultimate strength 215,000 lbs. = 4511 lbs. per square 
inch. 



32 



WJtite Oalc Post No. 2. 

Weight ^'^" ^^'^• 

Length 144 inches. 

Hiameler (outside; ^^ 



j Diameter of core ^-^ inches 

I Sectional area "'^•' ^'i- "^^* 

I Tested wUh pintle ends. 

I Counterweigbted at middle ITO pounds. 







Deki-ectioxs. 



1'..' ft. from N. end. 



Itor/on. ; Vertical. I Horizon. ! Vertical. 



o.O'O 
JO.tKX) 

8i),0(i0 
40,000 
".0.000 
fiO,00() 
70.000 
80.00') 
90,000 
100,000 
lOo.OOO 
110,000 
115,000 
120.000 

r2.=i.ooo 

1. so. 000 
13-1.000 
1 10,000 
14o,000 
1oO,0<lO 
l.V>,000 
IfiO.OOO 
160.000 
.5,000 
160.000 
lfi5,000 
170,000 
175,000 

i80,a>o 

ls5,000 
190,000 



190,000 

190.000 

5,000 





















—.02 
—.OH 
-.01 
-.01 
-.0'. 
—.06 
—.07 
—.02 
-.07 
-.OS 
—.08 
—.09 
—.09 
—.10 
—.12 





















— .0-) 
— .0(5 

-.or, 

-.07 
-.10 
-.12 
—.13 
—.05 

— .l.< 

—.15 
-.17 
—.18 
—.21 
—.2(5 
— .:«} 
f-.47 
I -.50 















+.02 
+.02 
+.02 
.03 
.01 
.07 
.OS 
.09 
.10 
.10 
.10 
.10 
.10 
.10 
.10 
.12 
.]:? 
.13 

.13 
.13 
.13 
.13 
.14 
.14 
.14 



1 '2 ft. from S. end. 1 
IIoriZv)n. ' Vertical, i 

















+ .03 

+.03 

+ .0i 
.01 
.05 
.05 
.0", 
.05 
.05 
.05 

.0'; 

M 
.0(5 
.0(5 
.0(5 

.or, 
.01 

M 

.or, 

.0(5 
.0(5 
.07 
.07 
,08 

.07 
M 















+.02 
+.02 
+.02 
.03 
.01 
.05 
.0<} 
.07 
.07 
.OS 
.0^ 
.09 
.10 
.10 
.10 
.11 



Slight snap'ng heard at 112,000. 



3 minutes' rest. 

4 min. rest. UU. stretigth. 



».i "L^i'„^L^.7'.^,?j'»Lt?rsr;;';r, iireSESiS; 'f!,3 'ir.',;?:;^''^ "o''i^.«s,„n p,aiform, or ... 



Pintles removed and post loaded with flat ends, ta«:ing 
testing machine. 



5,000 
.'-.0,000 
100,000 
150,000 
180,000 
190,000 
190,000 
190,000 
190.000 
190,000 
190,000 
5.000 



10 

.02 I I 

-.03 I +.05 I ! 

-.15 I .07 ; i 

-.35 .10 ; ! 

-.:« I .10 

-.50 i .10 

-.fi2 I .o«5 I I 

-.75 I .03 i : 

-.90 ! ' 

-.95 : 



3 minuses' rest. 

6 minutes' rest. 

9 niiinites' rest. 
12 minn'es' r^st. 
Ultimate strength. 



two knots near the middle of Us lenstb. 



33 



Wblte Oak Post No. 3. 

Weight 2CC lbs- 

Totallenglh 14U.2 Inches. 

Gauged length 140 inches. 

Diameter (outside; 8.2 inches. 



Dlaraoior of core l.Jj Indies 

Seoiionul area ikV. 2>q. incht-s. 

Eccentricity 1.91 inches. 

Same plate and rod used as wiih yellow pin.' i)ost No. 2- 
Counterwelghted at middle 120 pounds. 




1. 


Compression 
Inches. 


Permanent 
sets. 




DKJ--r,KCTI()NS. 




11 


Centre. 


2^^^ It. from centre , 
toward eccentric end.| 


Horizon. 


Vertical. 


Horizon. 


! 

Vertical. ! 

1 
+.01 

.as ! 
.11 > 

.17 ! 

.30 

..38 ! 
.48 i 
.60 ! 
.70 ! 
.75 j 
.80 i 
.82 i 
.88 
.95 
.98 


."i.OOO 




.0040 

.0130 

.0220 

.0318 

.0400 










s 






Q 












+.01 
.10 

'.18 

o" 

..30 
..38 
.46 
.60 
.70 
.75 
.80 
.83 
.90 
.98 
1.00 
1.10 
l.:iO 
1.62 






















10.000 




20.000 




30.000 




40.000 




50,000 




5 000 





60,(:k)0 




70.000 




80.000 




90.000 




90,000 
90,000 




90 000 


, 


90 000 


;;z;;r;:;'" 


95.000 
95.000 
95,000 


, 




ITO.OOO 




1.08 ; 


10),000 








1. 8 
1.70 


100,000 
100.000 





.5 minutes' rest. 
10 minutes' rest. 
18 minutes' re.st. 
23 minutes' rest. 

5 minutes' rest. 
8 minutes' rest. 

5 minutes' rest. 
15 minutes' rest. 
Ultimate strength. 



Failed bv deflecting upwards. Weakness developed at knots 
post. Test discontinued before mucli local weakness appeared. 



and generally throughout entire length of 



34 



IVhite Oak Block, No. 2. 

Total length 24.06 inches. 

Gauged length 18 inches. 

Diameter 9.98 inches. 

Sectional area 78.23 sq, ins. 

Weight 59 lbs. 




Loads ap 

plied. 

Pounds. 


Compres- 
sion. 
Inches. 


Perma- 
nent sets. 


Bemarks. 


5,000 




.0015 
.0060 
.0100 






10,000 


■ 




30,000 






50,000 
5,000 


.o664"" 




70,000 


.0140 
.0177 
.0197 




90,000 






100,000 






5,000 


.0006 




110,000 


.0215 
.0238 
.0260 
.0264 
.0285 
.0290 
.0310 
.0315 
.0336 
.0345 
.0364 
.0380 




120,000 






130,000 






130,000 






140,000 






140,000 






150,000 






150,000 




5 minutes' rest. 


160,000 




160,000 






170,000 






170,000 






2,000 




(rested 15h'rs; new 
Igaugings begun. 


5,000 


.0319 
.0382 
.0403 
.0415 
.0425 
.0439 
.0451 
.0469 
.0484 
.0512 
.0542 
.0630 
.0680 
.0735 
.0818 
.0867 
.0994 
.1030 
.1200 
.1240 
.1520 
.1620 
.2140 
.2240 




175,000 






175,000 






180,000 






180,000 






185,000 






185,000 






190,000 






190,000 




5 minutes' rest. 


200,000 




200,000 




5 minutes' rest. 
/Load sustain'd 6 m. 
_l before gauge read. 

5 minutes' rest. 

5 minutes' rest. 

5 minutes' rest. 

5 minutes' rest. 

5 minutes' rest. 

5 minutes' rest. 

f5m. rest. Fail, took 
I place very rapid 1 v. 
rUlt. strength = 3132 
\ lbs. per sq. inch. 


210,000 




210,000 




220,000 




220,000 




225,000 




225,000 




230,000 




230,000 




235,000 




235,000 




240,000 




240,000 




245,000 




245,000 




245,000 













IVIiite Oak Block.— No. 3. 

Total length 24 inch, 

Gauged length 18 inch' 



Diameter. 



.8.18 inch. 



.Sectional Area •. 52.55 sq. inch. 

Weight 41 lbs. 




Loads ap- 
plied. 
Pounds. 


Compres- 
sion. 
Inches. 


Perma- 
nent sets. 


Rkmakks. 






.0010 " 
.0072 
.0131 






5.000 






10,000 






3(»,0{)0 






50,000 






5.000 


.01)01 




60,000 
70,000 
80.000 


.0163 
.0196 
.0218 
.0222 
.0240 




90,0(0 
100.000 






5,000 


.0020 




110,000 


.03 5 
.0390 
.0465 
.0622 
.0845 
.0920 
.1180 
.1271 
.1790 
.1980 
.3240 




130.000 






140,000 






150,000 






150.000 




Afteromin rest 


155.000 






155,000 






160, roo 






160. 000 




After 5 min. rest 


165.0,00 






ia5,ooo 




After 5 min. rest. 


165,000 




fUh, .strength =3139 
libs, per sq. inch. 






■••••• — "-1 



Failed by crumpling the fibres and opening lon- 
gitudinal cracks. Rapid .vielding began after the 
maximum load had been sustained 8 minutes. 

Knotsat the middle of the block in the vicinity of 
the fracture probably located the place of failure. 



35 



nitlte Onk BlcM'k Xu. 4. 

Total li'iiylli 2:: "^ liichM. 

(Jauged IS inches. 

Diameter 7.73 liu-hos. 

S(*ctional uroa •W.gasq. ins. 

WeitclU -M lbs. 




Loads ap- 


Compres- 


))lied. 


sion. 


Pounds, j 


Inches. : 


5,000 ; 





10,000 : 


.0005 


20,000 


.0031 


30.000 


.(KV.l 


40,000 


.<109(( 


50,000 


.0119 


5,000 




«0.(X)0 


.014S 


70,000 


.Ol!i-) 


80,000 


.0209 


<)0.(X)0 


.0239 


100.0(X) 


.0270 


5 000 




110,000 


.0310 


120,00(1 


.O-i-Yi 


130.000 


.0400 


140,00) 


.0 S7 


1-JO.OOO 


.05<i0 


110.000 


.0605 


140.000 


.0650 


140,000 


.0099 


140,000 


.075(1 


140,000 


.0H2() 


140.000 


.000*» 


140,000 


.0990 


140.000 


.1102 


140.000 


.12(M 


140.000 


.1274 


140,000 


.1350 


140,000 


.1408 


145.000 


.14.J0 


145,000 


.1600 


150,000 


.1650 


irjO.OOO 


: .2040 


155,000 


.21.50 


155,000 


.3090 


155,000 ; 


.4550 



Perma- 
nent sets. 



Rkmahkk. 



.0010 j 

After 5 min. rest. 

After 10 min. rest. 

After 15 min. rest. 

After 20 min. rest. 

After 25 min. rest. 

After 30 min, rest. 

After .3.5 min. rest. 

After 40 min. rest. 

After 4.5 min. rest. 

'' After .50 min. rest. 

After 55 min. rest. 

After 60 min. rest. 

After 6.J min. rest. 

Afiej- 5 mm. rest. 

After 5 min. rest. 

! After 5 min. rest. 

i r After 10 min. rest. 

J LTlt. strgth 155,000 

( =33(.3 per sq. in. 



The maximum load, 1.55,000 lbs., had been carried 5 
minutes, lines of failure were visible. These lines 
were more rapidly developed as time pa.ssed by, 
crumpling the fibres rapidly after 12 minutes' time. 




Ko. 1911. 




Post No. 1914. 

Weight 113 

Length 144.92 

Gauged length l-iO 

Diameter of larger end , 6.84 

Diameter of smaller end 5.85 

Diameter of core 1.95 

Sectional area at larger end 33.8 

Sectional area at smaller end 23.9 

Post not straight, versed-sine at middle... 0.45 

Ends brought to an even bearing. 

Post had been in the mill about 63^ years. 



lbs. 

ins. 

ins. 

ins. 

ins. 

ins. 

sq. ins. 

sq. ins. 

ins. 



Loads 
Applied. 
Pounds. 



5,000 
10,000 
20,000 

5,000 
30,000 
40,000 
£0,000 

5,000 
00,000 
70,000 
80,000 
90,000 
100,000 

5.000 
HO.OOO* 



Compres- 
sion. 
Inches. 


Perma- 
nent Sets. 


Dkfjlkctioxs. 


Horizon. 


Vertical. 




.0112 
.03J) 





.08 

.10 
.15 

.17 






.0006 






.0958 
.09 2 
.1204 

ii480 

.1702 
.2050 
.2345 

.2(i40 















.0010 




.22 
.25 
.30 
.40 
.55 
.10 


.05 




.07 
.10 
.13 
.10 


.0062 











* Ultimate strength ; equals 4602 lbs. per sq. in. ; sus- 
tained about three minutes. 

Horizontal deflection follows initial bending, When 
the maximum load had been sustained three minute s, 
the deflections gradually increasing, failure suddenly 
occurred, by the fibres giving way in the vicinity of 
some knots 60 inches from smaller end. The fibre of 
the wood has a dull, dead appearance. 



Po.st Xo. 1915. 

Weight 110 lbs. 

Length 144.92 ins. 

Gauged length 140 ins. 

Diameter of larger end 0.85 ins. 

Diameter of smaller end 5.85 ins. 

Diameter of core 1.90 ins. 

Sectional area at larger end 34 sq. ins. 

Sectional area at smaller end 24 sq. ins. 

Ends brought to an even bearing 

Post had been in the mill about 0'^; rears. 



Loads 


Compres- 
sion. 
Inches. 


Perma- 

neiii teeis. 


DCFLKCTIOXS. 


Applied. 
Pounds. 


Horizon. 


Vertical. 


5,000 
10,000 




.0112 
.0345 








—.05 



-.00 
—.10 
-.10 


—.10 
-.10 
-.10 
—.12 
—.12 


—.12 

=1 






20,000 







5,000 








30,000 


.0570 
.0790 
.1010 





40,000 
50,000 











5,000 


—.0010 





00,000 


.1225 
.1445 
.1670 
.1884 
.2113 





70,000=:= 







80,000 
90,000 





-i-.08 
+.12 


100.000 




+:i2 


5,000 


-.0040 





110,000 




+.12 


120,000 




+.12 


130,000 




+.12 


140,000 




—.05 


145,0001 







^Snapping sounds. 

tUltimate strength; equals 6032 lbs. per sq. in. 
Failed by bending downwards. Fibres crumpled at 
knot 12 inches from smaller end. Opened longitudinal 
crack 41 inches from same end. At this point (42 
inches from end) tlie maximum deflection took place 
when the maximum load was first passed. After con- 
tinuing the deflection to —3 inches vertical deflection, 
the piAximum deflection was near the middle. 



0/ 




No. rji(i. 




No. 1917. 



Post :v«. lOlG. 

Weight 118 lbs. 

Length ;.. 1 145.4 ins. 

Gauged length 140 ins. 

Diameter of larger end n.TO ins. 

t)iameter of sniallef end 5.87 ins. 

I)iameterof eore. 2 ins. 

Sectional area at larger end .S2.1 sq. i 

Sectional area at smaller end 23.9 sq. i 

About 20 inches from smaller end max- 
imum versed-sine 0.25 ins. 

Short bends in post. 

Knds brought to an even bearing. 

Post had been in mill about 6'a years. 





Compres- 
sion. 
Indies. 


Perma- 
nent .sets. 


Deflkctions. 


Applied. 
Pounds. 


Horizon. 


Vertical. 


5,000 
]0.f)0() 




.Olio 

""""0754 

.1022 








—.05 



-.10 
-.10 
—.10 

-.Ifi 

—.20 
—.25 
—.(V) 
—.32 
-.50 






20,<:00 
5,0:0 
30.000 
40,IXK) 


' "o 


—.05 


—.10 
—.10 


50,1300 




-.10 


5,(X)0 


.Oul5 





fiO,(X« 
70,' 00 
80.000 
'JO.O'JO 
,000 


mm 


—.10 
-.14 
—.20 
—.25 


.0108 





] IX) ,000 




—.32 


110,000 




—.45 


112.000* 







* Ultimate strength ; equals 4682 lbs. per sq. in. 
Failed at seme knots 25 inches from small end. 
Dtfl 'clcd downwards. 



Post No. 1917. 

Weight 113 Iba. 

Length 144.6 ins. 

Gauged length 140 ins. 

Diameter of larger end 6.75 ins. 

Diameter of smaller end 6.02 ins. 

Diameter of core 1.9J ins. 

Sectional area at larger end 32.8 sq. ins. 

Sectional area at smaller end 25.5 sq. ins. 

At 3 feet from large end versed-sine 0.50 ins. 

Short bend near large end. 

Tested with maple cap and oak base with grain at 
right angles to axis of post. 

Ends not brought to an even bearing. 

Post had been in the mill about 6>2 years. 



Loads 
Applied. 
Pounds. 



5,000 
10,0(X) 
20,000 

5,000 
30,000 
40,000 
50,000 

5,000 
60,000 
70,000 
75,000* 



Compres- 
sion. 
Inches. 


Perma- 
nent sets. 


Deflections. 


Horizon. 


Vertical. 




.0075 
.0.,15 







-.02 
—.09 





+.ft5 




09 


—.0020 





.0585 
.0895 
.r255 


"— .'i'6 

—.07 


.13 

.14 


.0050 





.1670 

.2*58 

1 



+.35 


.10 
-.05 



* Ultimate strength; equals 2943 lbs. per sq. in. 

.Sustained maximum load about 3 minutes and tl.en 
failed rapid y, deflecting sideways to the west and 
downwards. Fibres crumpled at two knots at middle 
of post. The knots were on the concave side. Maple 
cap and oak base were most deeply indented on the 
west side. The deflection of the post was continued 
till the ends were relieved of their bearings on the ea.st 
side of caps and base, the load being carried on the 
indented sides of cap and base. 



I 





No. 1931. 



Post No. 1918. 

Weight 108 lbs. 

Length 144.8 ins. 

Diameter of larger end 6.88 ins. 

Diameter of smaller end 5.75 ins. 

Diameter of core 1.95 ins. 

Sectional area at larger end 34.19 sq. ins. 

Sectional area at smaller end 22.98 sq. ins. 

Post not straight. Versed-sine at middle 1 in. 

Compressions not measured. Tested with maple cap 
and oak base. Large end of post in a state of partial 
decay, reducing bearing surface to about one-fifth full 
section of end. Post had been in mill about G}4 years. 





Deflections. 












Appld. 






Remarks. 


Pounds. 


Hor. 



Vert. 

1 




5,noo 


Post placed in machine con- 


10.000 


-f.05 


i —.15 


vex side up. 


20.000 


.20 


! -.30 


At large end bearing takes 


30.000 


.89 


i —.40 


place at upper side only. 


40.0(M) 


.64 


1 —.50 




50.000 


.85 


i —..55 




60.000 


1.05 


1 —.45 




70,(M)0 


J. 35 


1 -.22 




75.000 






Ult. Rtg. = 3263 lbs. per sq. In. 



Failed by deflecting horizontally and upward. Maxi- 
mum load sustained about 2 minutes. As the loads 
were increased above the initial load of 5000 pounds, 
the fibres at the larger end gradually crumpled, till 
finally the post took a full bearing. After bearing the 
maximum load, deflections were increased till the 
fibres were broken at knots 20 inches to 40 inches ffom 
small end. 



Post ITo. 1931. 

Weight 118 lbs. 

Length 144,10 ins. 

Gauged length 140 ins. 

Diameter of larger end 6.74 ins. 

Diameter of smaller end 5.97 ins. 

Diameter of core 1.92 ins. 

Sectional area at larger end 32.78 sq. ins. 

Sectional area at smaller end 25.10 sq. ins. 

Ends not brought to an even bearing. 

Tested with maple cap and oak base. 

Post had been in mill about G'4 years. 



Loads 


Compres- 
sion. 
Inches. 


Perma- 
nent Sets. 


Deflections, i 


Applied. 
Pounds. 


Horizon. 


Vertical; 


5,000 
10,000 




—.0020 
.0008 






—.08 
—.14 
—.04 
—.20 
—.25 







-l-.io 


20,000 
5,000* 
30 OOOt 




-I-.20 


— .(wois 







.25 


40 ODO 






..30 


50,(XK) 







—.30 
-.40 
—.46 
—..55 
—.65 
—1.05 


..^1 


60.000 






.40 


70 000 






.42 


80,0(X) 
90,000 






.46 






.55 


100,0(X» 







.75 


106,0001 












* Micrometer removed. 

t Cracking sounds heard. 

J Ultimate strength ; equals 4i.'23 Ib.s. per sq. In, 

Failed by deflection; opened longitudinal seams. 



39 




Xo. 1932. 



Ponf XO. 1032. 

Weight 118 lbs. 

Length 140.6.5 ins. 

Gauged length NO ins. 

Diameter of smaller ei.d 6.10 ins. 

Diameter cf larger end Ci.Si ins. 

Diameter of core 2 ins. 

Sectional area of smaller end 2(>.08 sq. ins. 

Sectional area of larger end 33.3 sq. ins. 

Tested with maple cap and oak bsise. 

Ends not brought to an even bearing. 

Post had been in mill about G'- years. 





Dkfi>kctions. 




r^uds 








Appl'd 






R K.MARKS. 


Pounds. 


Hor. 


Vert. 




.i.ooo 










10.000 










20.000 


.0.5 


.0.5 




.30,000 


.08 


.06 




40.000 


.10 


.10 




50.000 


.15 


.10 




60.000 


.20 


,05 




70,000 


.35 







80.000 


..5.5 


-.05 




{K),000 


1.40 


-.30 


Ult. stg. = 34.50 lbs. per sq. in 



Failed at tAA'o knots at middle of post ; knots were on 
the concave side. 



OLD WEITE OAK F08TS FROM MILL No. 2 (PACIFIC MILLS). 




Post A. 



Post A. 

Weight 393 lbs. 

Length 166.70 ins. 

Diameter 10.54 ins. 

Diameter of core 1.9 ins. 

Sectional area. 84.4 sq. ins. 

Post not straight, versed-sine 1.6 ins. 

Ends not brought to an even bearing. 





Deflections. 




Loads 




1 




Applied. 






Remarks. 


Pounds. 


Hor. 


Ver. 




5,000 










10.000 


-.06 







30,0(W 


—.20 







50,000 


—.26 







70,000 


—.30 







90,000 


—.2^ 







100,000 


-.28 







120,000 


-.28 







140.000 


-.25 







160,000 




— .ft5 




180,000 


—.20 


—M 




200,000 


-.18 


— .a5 


Snapping sounds. 


220,000 


-.10 


—.05 




240,000 


-.08 


—.05 




2(»,000 


-.02 


-.05 




2.80.000 


+.02 


-.06 




.300,000 


.10 


-.08 




3-20.000 


.18 


-.10 




.340,000 


.25 


-.10 




.360,000 






Ult. atg.^4265 lb. per sq.In. 







Failed suddenly, opening a longitudinal seam. Brok« 
with a loud report. 



40 




Post B. 




Post C. 



ro t 15* 

Weight SCO lbs. 

Length 165.4 ins. 

Gauged length 140 ins. 

Diameter 10.50 ins. 

Diameter of core 1.9 ins. 

Sectional area 83.70 sq. ins. 

Post not straight, versed-sine about 0.40 ins., hori- 
zontal deflection, and about 0.40 of an inch vertical, 
both in minus direction. Stick has winding grain and 
season cracks filled with putty. Ends not adjusted to 
even bearings. Under initial load at north end upper 
side of post 0.20 of an inch short. South end upper side 
0.15 of an inch short. 



Doads 
Applied. 
Pounds. 



10/00 
20,000 
30,1100 
40,000 
50,00it 
10,(X)0 
70,0(H) 
90,000 
100 Of W 
10,000 
120.000 
140,000 
160,000 
180,000 
200,(100 
10,000 
220,000 
240,000* 
26ii,0<i0 
280,000 
300,(0) 
320.000 
.S25,000t 



Compres- 
sions. 
Inches. 


Perma- 
nent Sets. 


JjKri.ECTIONS. 


Horizon. Vertical. 




—.0105 
-.0-^05 
—.0260 
-.0275 





.08 
.10 
.15 
.15 

",.5 

:11 


.12 
.12 
.10 

.08 
.06 




-02 
—.05 
-.0-5 
—.12 












.05 




.15 

.15 


—.0015 





-.0260 
—.0232 
—.0200 


.20 








.28 


-.0020 





—.0130 

—.0032 

+.0080 

' .0212 

.0300 


.32 




.35 





.38 




.40 




.40 


.0030 








.52 






.55 






.60 






.60 






.60 


1 




.60 


1 


::::::"::::::::: 





* Snapping 'bounds. 

t Ultimate strength ; equals 3880 lbs. per square inch. 

Placed in machine with concave side up. Failed by 
splitting at end on the convex side. Up to 200,000 lbs. 
load, the cuds had not come to a full bearing. 



l*ost C. 

Weight 3S3 lbs. 

liength 168 ins. 

Gauged length 140 ins. 

Diameter ,. 10.54 ins. 

Diameter of core 1.95 ins. 

Sectionalarea 87.26 sq. l 

Ends not brought to an even bearing. 



Loads 
Applied. 
Pounds. 



,000 
,000 
,000 
,000 

,(;oo 

,000 

,000* 

,000 

,000 

,000 

,000 

,000 

000 

,000 

000 

,000 

,000 

,000 

,000 

,000 

,000 

,000 

,000 

,000 

,000 

,000 

,000 

,000 

,ooot 



Compres- 
sions. 
Inches. 


Perm fl- 
uent Sets. 


Deflections. 


'. lorizon. 


Vertical. 



.0044 

.om 

.0310 


; •;■;••;;• 





.10 
,10 


.10 
.10 
.10 


.10 
.10 
.10 



.12 
.15 
.15 



.18 
.20 
.20 
.20 
.20 
.22 
.25 
.28 
.28 
.30 
.31 






.05 
.05 


.0010 





.0478 
.0640 
.0720 


.05 




.05 




.05 


.0015 





.0890 . 

.ia55 

.1141 


.a5 




.05 


... 


.05 


.0016 





.1300 
.1472 
.1560 


.05 




.0.5 




.05 


.0020 







.05 




. 


.05 




:::::::::::::::::: 


M 






.05 






.05 






.Oo 






.05 






.05 






.10 






.10 








1:::::::::::::::::: 




.15 



=-=Snapping sound. 

fUltimate strength; 4^84 lbs. per sq. in. 
Failed at knot about 5 feet from end. Post appeared 
shaky near this failure. 



41 




Post I> 

Weight 388 lb«. 

Ler.sl'.i IOC)..-, ins.. 

GauccJ Ic nslli 1^0 Ins. 

Diameter Ki.V! ins. 

Dian;eier of coi\' 1.9 ins. 

Sectional area M.7 sq. ins. 

Ends broujjht to even bearing by usinj,' brass packing. 

' Di.:fi.ectioxs. 

Loads I Compres- ; pprn.a- ' 

Applied. sloiis. I .i,,^'^"'^,^ 

Pounds. > Inches, t^^ ''"^- Horizon. Vertical. 



5,000 



.OOSO 
.0320 
.a').o 

































—.08 
—.10 



-.10 
-.15 
—.18 



—.20 
-.22 
-.30 



-.30 
-.40 
—..-.0 
—.50 
—M 
— .tiO 
—.Go 
-.SO 
-1.40 






30, <K) 







50,000 









.0030 





7o.i>.(i 


.OTtiO 
.0980 





yo, 00 







10 '.0 







(K» 


.()o:i5 





1 »'.(XXJ 


.131.-, 
.1-540 
.IGoo 





140.000 







i.iu.ooo 







O.UOO 


.004., 





170,oO) 


.18t>.i 
.-'100 
.2225 





190 000 




05 


20<J.iX)0 




.10 


rt 0(»0 


.00.0 





22»>000 


24«0 
.2/15 
.28«0 


+.10 


24(),0«tO 





+.12 


25U.0U0 




+.12 


5,000 
270.000 
290.1XX) 


.OOiX) 




.3110 
.3410 
.;io70 


.12 
.1--, 


300,(HiO 




15 


o.OOO 
32^),0(X1 


.0180 



15 


34().l)(X) 






.15 


34-").0fX)* 






.15 


35<l.0tJO 






.15 


3'".0.0(X) 






.15 


370.' KJO 






.15 


:^o,oo>t 






.12 


390,1100 






OS 


390.(KX)t 









390.000t 



















♦Sustained five minutes. 

tAfter sustaining load five minutes. 

tUltimate strength ; 4C04 lbs. per sq. in. 

Failed by deflection, sidewaj-s, at knot, six inches 
from end ; after passing the ma.ximuni load, the pre.ss- 
ure wa-s allowed to fall off tf> .■'^S0,0(lO lbs., and was main- 
tained at this point about three u.Inutes. Snapping 
sounds were heard frccpiently after pa.ssing 120,000 lbs. 
Conve-x side, after failure, on the side, huvlni; knot six 
Inches from end. 



Post E. 

Weight 3 lbs. 

Length 107.04 ins. 

Gauged length 140. ins. 

Diameter 10.20 ins. 

Diameter of core 1.8 iu.s. 

Pintle length 19.60 ins. 

Se'ctional area 79.17 .sq. ins. 

Ends not brought to an even bearing. Tested with 
base at one end ; pintle and cap at one end. 



I I Dkfi.kct:ons. 

Loads Compres-' pp-™„ ! 

A pulled. sions. neiit sets ' 

Pounds. Inches. "^"^ ''**^^- Horizon. Vertical. 

~1 i I . 

10,000 j I ; 1 

20,00.1 ,0100 1 • 

30,000 I .0220 1 

50.00) i .04.,0 : —.02 I —.02 

10,000 , ' .0(^)05 I 

70.000 .0fi.S(i —.'2 ' —.05 

90.000 i .0910 —.05 —.OS 

loo.aw 1 .1018 —.0.5 : —.10 

10,000 : ! .0018 1 

120,000 I .12 —.05 i -.12 

140,000 .1400 — (M! ! —.15 

lOO.tXK) AHm —.08 i —.10 

180 000* .1910 I —.10 ! —.16 

2(R).0(;0 I .2140 —.10 i —.18 

10,(X)U : I .0036 i ; -.08 ' 

220.000 i ' —.10 I —.20 

240,000 : —.13 ; —.24 

2«).0O0 i i —.15 i —.25 

280,iK)0 i —AS —.28 

300,)00 , —.22 ; —.30 

320,0')0 — .2S ! —.y.i 

340.(X)0 1 —.30 I —.36 

3GO,0(J0 ' ' — .H4 —.40 

370,0001- I ■ '< —.80 i —.42 

*Snapping sounds. 

tUltimate strength; 4662 lbs. per sq. in. 

Failed suddenly at a knot 10 inches from the end 
used without pintle, crumpliug the fibres and opening 
lougitudinul seams. 



42 




Post F 




Post G. 



Post F. 

Weight 378 lbs. 

Length , 1C7.63 ins. 

Gauged length 140 ins. 

Diameter 10.40 ins. 

Diameter of core 1.7 ins. 

Sectional area 82.68 sq. ins. 

Tested with cap and pintle at one end; base at the 
other end. Ends not adjusted to an even bearing. 



Loads 
Applied. 
Pounds. 



400, 



,000 

,000 

,000* 

,000 

,000 

,000 

,000 

,000 

,000 

,000 

,000 

,000 

,000 

,000 

,000 

,000 

000 

,000 

000 

,000 

,000 

000 

000 

000 

000 

ooot 



Compres- 
sions- 
Inches. 


Perma- 
nent Sets. 


Deflections. 


Horizon. 


Vertical. 




.0160 
.0461 








-.03 
—.04 
—.08 















.0040 





.0632 
.0789 
.0872 


.13 




—.08 


.15 




-.08 
-.08 
—.12 
-.12 
-.12 
—.15 
—.15 
—.15 
—.25 
—.26 
-.30 
—.40 


.18 


.0050 


.20 


.1040 
.1200 
.1362 
.1513 
.1670 


..33 




..36 




.40 




.40 




.43 


.0052 


.40 




.80 






.80 






.90 






m 






—.40 i 1-0() 






-.40 
-.40 
-.40 
—.40 
—.42 
—.45 


1.00 






110 






1.20 






1 30 






!.:« 






1.36 








—.46 1 1.55 



♦Snapping sounds. 

tUltimate strength ; 4838 lbs. per sq. in. 

Sustained maximum load about 5 minutes. Failed 
by splitting post at pintle end, fracture occurring from 
12 inches to 24 inches from end, Deflections Increased 
after reaching maximum load. 



Post G. 

Weight 301 lbs. 

Length , 16-1.2 ins. 

Diameter at ends 9.35 ins. 

Middle diameter 9.3 ins. 

Diameter of core 1.95 ins. 

Sectional area 64.94 sq. ins. 

Post not straight from end to end. One end takes 
full bearing, the other end bearing on lower side; open 
at top about 0. 1 inch. 





Deflections. 




Loads 






Applied. 






Remarks. 


Pounds. 


Hor. 


Ver. 




10,000 










20,000 


.05 


.02 




30.000 


.06 


.06 




40,000 


.OS 


.10 




50,000 


.09 


.11 




60,000 


.10 


.13 




70,000 


.10 


.14 




80,000 


.10 


.15 




91,000 


.11) 


.16 




100,000 


.10 


.16 




110,(K)0 


.10 


.17 


Snapping sounds. 


120,000 


.10 


.18 




130,000 


.10 


.19 




140.000 


.11 


.20 


• 


150,000 


.12 


.20 




160.000 


.12 


.20 




170,000 


.12 


.20 




1HO,000 


.13 


.20 




1!K),000 


.13 


.20 




200,000 


.14 


.20 




2]0,000 


.15 


.20 




220,000 


.15 


.20 




230,000 


.16 


.20 




240,000 


.17 


.20 




250,000 


.18 


.20 




260,000 


.19 


.19 




270,000 


.20 


.17 




280,000 


.20 


.15 




290.000 


.21 


.13 




300,000 


.23 


.10 




310.000 


.30 







317,000 








Ult. stg.=48811b. persq.In. 



Tailed at some knots 5 feet from end. 



/'/'^ 


: .A 


^Bl 






a 






^ 


.(sr- 


1 9':5 


S?' 


2.5 




ivi=^ 


r 


^^=- 


ii-i 


»/^^ V 


16-^' 


m 


i. 






_->/ 



Post H. 




Post I. 



po«t H. 

Weight 293 lbs. 

Length IW.OS ins. 

Diauieierui lop 9.5 ins. 

Average diameter 9.23 ins. 

Diameter of core 1.9 ins. 

Sectional area 64..37 sq. ins. 

Post not strai.LTht from end to end. Upper end lakes 
an even hearing; lower end bears on one side, about 
0.08 of an inch olT at oiher side. 



Loads 
Applied. 
Pounds. 



Deflectioxs. 



Hor. Ver, 



Rkmarks. 



OIK) 
1)00 

(XX) 

«)00 
OlMI 

ato 

()00 

,(XKt 

,000 

,000 

,000 

,000 
,000 
,000 
.000 
000 
tXW 
000 
000 
,(>tK) 
,000 

coo 





—M 
—.14 



—.04 


—.20 


-.Itt 


-.20 


— .Ofi 


-.20 


— .0(i 


-.20 


-.08 


-.20 


—.08 


— .21 


—.10 


,21 


-.10 


_'jl 


-.11 


—.21 


—.12 


—.21 


— l-i 


— 21 


-.14 


-.20 



/ Lower end taJces full 
I. bearing. 



Snapping sounds. 



Ult. Btg.— 3433 lb. persq.ln. 



Took triple ( ?) flexure towards end of test. Deflec- 
tions not measured at maximum points. Deflection 
continued till post suddenly broke about 42 inches 
from end. 



P«»t I, 

Weight 207 lbs. 

Length ,,. 163.3 Ins. 

Diameter 9.4 iua. 

Diameter of core 1.9 ins. 

Sectional area ,.,. 66.56 sq. ins. 

Post not straight from end to end. Ends do not take 
a full bearing. Open about 0.08 »,t top, each end. 



Loads 
Applied. 
Pounds. 



000 

000 
000 
OOO 
,(XlO 
000 
,000 
,000 

,000 

,000 
,000 
,000 
,000 

,ooe) 

,000 
,000 

,aio 

,000 
,000 
,000 
,000 
.000 
,000 
.000 
,000 
,000 
000 



Deflectioxs. I 



.12 
.13 

.10 

.17 
.18 
.19 
.20 
.20 
.20 
.20 
.20 
.20 
.20 
.20 
.20 
.19 
.19 
.18 
.18 
.17 
.17 
.16 
,16 
.16 
.16 




.01 
.03 
.05 
.06 
.07 
.07 
.07 
.06 

.o.> 

.04 
.02 



—.02 
-.04 
-.06 
—.10 
—.11 
-.15 
-.18 
—.24 
-.30 
-.31 



Knds take full bearing. 



.13 I Ult. 8tg.=3981 lb. persq.ln. 



Failed by deflecting downward. Sustained maxi- 
mum load 5 minutes, deflection increasing rapidly 
near the close of the teat. 



. 44 




Post J 



OLD WHITE OAK POSTS FROM MILL No. 3. 




Post J. 

Weight 310 lbs. 

Length „..,. , 163.8 ins. 

Diameter „.,„., 9.35 ins. 

Diameter of core ,....,...,,,...., 1.9 ins. 

Sectional area ,, (io.83 sq. ins. 

-Pos not straight from end to end. Tested with 
pintle at each end. round base between pintle and 
post at one end; rectangular cap between post and 
pintle at the other end. Pintles placed with major 
axis horizontal. 

Length ofpintle , 19.7 ins. 

Outsidedimensionsof section of pintle 5x8,5 ins. 

Insidedimensionsof section of pintle..,,,, 3.75x7.1 ins. 

Post takes full bearing at the bottom on base, base 
standing off from pintle about 0.10 ins. under side. 
Uneven bearing at the top standing off in places 
about 0.20 ins. from cap. Side of post about 40 ins. 
from one end gouged out to a depthof % ins. and 20 ins. 
long. 





Deflections. 


Loads 






Applied. 






Pounds. 


Hor. 


Ver. 


10,000 








20,00. » 





-.06 


30,000 


-.03 


—.10 


40,OjO 


-.OG 


-.12 


50,000 


-.10 


—.15 


(J0,000 


—.10 


—.16 


70,003 


-.12 


-.17 


80,000 


-.14 


—.18 


90,000 


-.18 


—.18 


100,000 


—.20 


-.18 


110,000 


-.22 


—.10 


. 120,000 


-.26 


-.13 


130,000 


-.28 


-.12 


140,000 


-.30 


—.10 


• 150,000 


-.S3 


-.10 


li30,000 


-.38 


— 07 


170,000 


—.40 


—.05 


180,000 


—.46 


—.02 


190,000 


—.52 





200,000 


—.60 


+.02 


210,000 


—.70 


+.10 


214,000 







100,000 






214,000 


-.iiS 


.M 


215,GDi> 


-1.10 


.8J 



Remarks. 



f Sudden snaps Increfts- 
1 ingver. Ueflectiou, 



Ul.stg.— 320Clb. pev,sq,lH, 



Sustained nia-ximum load 5 minutes. Deflected, fol- 
lowing the initial bend in post The side gouged out 
being on the concave side. Cast iron base found tO 
be split when post was removed from machine. 



OLD WHITE OAK POST FROM MILL No. 3. 



Weight 121 lbs. 

Length 138.2 ins. 

Diameter of larger end , 7.110 ins. 

Diameter of smaller end 5.98 ins. 

Diameter of core , , 1.62 ins. 

Sectional area of larger end 38.65 sq. ins. 

Sectional area of smaller end , 26.03 sq. ins. 

Compressions not measured. 





DEFIiECTIOXS. 




Loads 






Applied. 






Rem-vrks. 


Pounds. 


Hor. 


Ver. 




5,000 










10,000 





—.05 




20,000 


+.05 


-.10 




30.000 


.05 


-.13 




40,000 .. . 


.01 


—.15 




50,000 


.05 


-.15 




60,000 


.10 


-.20 




70,000 


.10 


-.20 




80,000 


.10 


-.20 




90,000 


.10 


-.20 




100,000 


.10 


-.25 




110,000 


.10 


-.30 




120,000 


.16 


—.30 




1*1,000 


.20 


— .oi 




140,000 


.2-J 


-.40 




150,000 


.35 


-.52 




160,000 






Ult.stg.-61471b. persq. In. 



I 



Sustained maximum load about three minutes; 
then failed suddenly, deflecting downward. Fibers 
crumpled at knots fi-om 22 inches to 32 inches ttoxjx 
smaller end, and longitudinal cracks were opened. 



45 



sEcors'i> sE:iti£:s. 



(i io:s5 




WuiTK Oak Post No. 1. 




White Oak Post No. 4. 



ee:cnd series. 



\inhilt« Oa3c Post Xo. li. 

Weight -lol Ihs. 

Length ...........iw.i..n-..i.v.......i, 141.4 ins. 

Gauged length.. ..v. 140 ins. 

Diameter 10.!-") ins. 

Diameter of core..... 16 ins. 

Sectional area 02.16 sq. Its. 

Tested with one flat end; one end with rounded 
bearing; vertical axis placed eccentric 2.75 ins. 





Deflkctioxs. 




Loads 






Applied. 






Remarks. 


Pounds. 


Hor. 


Ver. 




10.000 










20.000 










40.000 


.10 


.04 




50,000 


.12 


.05 




10,000 










70,000 


.20 


.10 




90,000 


.22 


.12 




100,000 


.26 


.12 




10,000 





.10 




120.000 


.?0 


.15 




140,000 


.40 


.16 




150,000 


.45 


.20 




10,000 





.15 




170,000 


.52 


.40 


Ultimate strength. 



Wliite OaU I»osl Xo. 4. 

Weight 200 lbs. 

Length 144 ins. 

Gauged lengthy 143 ins. 

Diameter 7.74 ins. 

Diameter of core » 1.60 ins. 

Sectional area 45.04 sq. Ins. 

Ends adjusted to even bearings. 



Loads 
Applied. 
Pounds. 



10,000 
20,000 
40,000 
£0,000 
10,000 
70,000 
90,000 
100,000 
10,000 
120,000 
140,000 
145,000* 



* Ultimate strength; 3219 lbs. per sq. in. 

Failed by deflecting horizontally and downward. 



Compres- 
sions. 
Inches. 


Perma- 
nent bets. 


Deflections. 


Horizon. 


Vertical. 



- .0200 
.0618 
.0825 

'.1258 

.1733 
.2000 










.02 
.02 
.10 
.10 
.10 




















.0025 



— 04 




— 06 




— 10 


.6138 


—.20 


.2550 


—.30 




—.60 









Crumpletl fibres and split post at end, on side receiv- 
ing eccentric loading. 



46 




■ 

White Oak Block No. 1. 

IVIiitt' Oalc ISlock No. 1. t'llimate strenurth Pinah llf'-OOO lbs-, einals 4i"j") lb» 

Wei'^ht "•'! Ilis. per sq. ill, (.'rumpled lilires near ihe oud uf block. 

Li n-tb -I ii.s. 

Diameter 1 10.01 ins. 

Sccii<;nal a ra »::. !S sq. in-. 




Yellow Pine Square Post No. 1. 

Yellow rine Aiqiiare Post Jfo. 1« 

Weight .....; ^SO lbs. 

Letigtb -.. 15;13 ins. 

Graigf-d lenrj^tb :.,..;,:,... 1 iO ii.s. 

Ilcctangnlar section ;.: 8.7Jx8.9-2 ins. 

Dianaeter of core -. ; 1.' ins. 

St'ctional area : * 76.01 sq. ins. 

Tested with one flat end: one end with roundM 
bearing; vertical axis eccentric^ 2:i') inches. PkHdiuS) 
rounded end, 4 inches. 



i J)KKI,K(TI<^XS. 

Tjoads I 

Applit-d. I 

Pounds, i J lor. Ver. 



MHM) 
I.IHW 
I.OIKI 
I.OOO 

•,0)0 

I.OiHJ 
1.0 






— .'« 
— !ii8 



IlKMARKS. 



Snstain(xl maximum load about two minutes. I'ailed 
by crumpling the fibres six inches from end on side 
receiving the eccentric load, and splitting post" at end. 



.28 


-.(W 


..TJ 


—.(13 


.40 


— .Oo 


.4S 


-.03 


.•» 


—.03 


.«0 


-.03 


.70 


—.03 


.7S 


—.03 


.91} 


—.03 



Ultimate Rtrbrij^th. 



47 




Yellow Pine Square Block 



Yellow Pine Kqnare Rlock >o. 1. 

tV'ei^hf S3 lbs. 

Loiigth 24 insi 

Hf'ctsinK'u'nr swtion : 8.08x9.02 ins. 

Seciioiml aroa : 81 sq. i 



T'llimato p' pn^th equals 1 2,ooo lbs., rqua'.s '^XjO V 
I'vx !<q. 111. Failed 1 y crumpling fibres. 




Yellow Tine Squaee Post No. 2. 



Yellow I*jnc .^«^narc Post Xo. 2. 

Weight 128 lbs. 

Length 154.23 ins. 

Gauged length 140 ins. 

Kectaugular section 10.05x10.13 ins. 

Diameter of core l.tJOins. 

Bectional area 99.8 sq. ins. 

Tested with one fiat end, one end with piritle. Same 
pintle used as on column Irom Mill No. 2, marked IZ; 
8. t-i Inches, axis of pintle vortical, upper edpe planed 
off 1-16 of an inch, uniform taper and at lower edge. 



Loads 


C«)mpre3- 

MOllti. 

Inches. 


Perma- 
nent t^ols. 


Dkklectioxs. 


Ai»pii«d. 
Pounds* 


Horizon. 'Vertical. 


10,000 



.0025 
.0076 
.0140 
.0220 
.0322 








-.03 
—.06 
—.06 
—.08 







20.000 







'W,000 




05 


60,000 






80,000 




■j^ 


100 000 




18 


J 0:000 





n 


i20,(JOO 


.iM:i5 
.05.)8 
.0690 
.0S22 
.09()0 


—.10 1 "n 


1 40,000 




—.10 
—.10 
-.10 
—.10 


-.12 
—.12 
—.12 
-.12 
-.15 
-.16 
-.18 
-.20 
—.20 
—.20 




160,000 
180,000 
200,00 1 








.20 
"0 


10.000 
220,00^1 
2 tO,000 





_ 
!25 


260,000 






.2.5 


280.000 







.25 


;ioo.(MHi* 








320,000 






•'6 


;<U),ooo 






"6 


3i;o.O(K) 






.•■8 


sso.oco 






28 


4<)0.0(M) 






•■< 


420.0 lO 






—.20 .28 


440,000 






—.20 '• .^i 


46().0(HI 






—.21 1 .3H 


4H0.01XJ 






32 .18 










510,(K)0t 


, 







^Snapping souhds. 

tUltimate strength; 5220 lbs. per sq. in. 

Failed by horizontal deflection and upward crui 

pled librcs hear middle of post. 



48 




Yellow Pine Square Block No. 2. 



YcTloiv I^ine Square ItIo<;k No. 2. 

Wpight 02.-} lbs. 

Length 24.00 ins. 

Rectangular section 1 1.2x10.07 in=;. 

Seoiioual aiea.. 102.7 sn. ins. 



Ultimate strength, 560,000 lbs., equals 5452 lbs. pe» 
sq. in. Failed by crumpling fibres. 




Vkllow Vise lio uxd i'osx ^so. o. 



Yellow Pine Bound Post K^o. S. 

Weight 213 Ib:^, 

I-ength :.; iG7.9 ins. 

Gauged length 140 ins: 

Diameter , .,„... .....i... 7.9 ns. 

Diameter of core 1.60 ins. 

Sectional area 47.01 sq. irts. 

Tested with flat ends. This post was sawed down 
from 1 Gleet long. 



lioads 
Applied. 
Pound.s. 


Compres- 
sions. 
Inches. 


.0136 
.0275 
.0415 
.0.560 


Perma- 
nent Sets 


' DKFLECTIOIsrS. 

Horizon. 1 Vertical. 

1 


10.000 
'20,000 
30,000 


i 
i 6 

> 


1 

; 
; ■) 

i 

; •'51 

; .03 

1 

.OS ■ 
i .10 

.10 
1 .10 

.12 

.10 
! .18 

.18 
i .18 
' ,18 
1 .10 


! 

I 

i 


40,000 
50,000 
10,000 




i 




1 


.0010 


1 


60,000 


.07CJ0 
.0868 
.1011 
.1162 
.1320 





70,000* 
80.000 









90,000 
100.000 









10,000 


.0030 





110,000 


.1480 
.1650 
.1815 
.1990 
.2160 


—M 


120,000 

r-ioooo 




—.10 




—.10 


H0,<'()0 




—.10 


1,50,000 
10,000 




— 12 


.0072 


—.10 


160,(X)0 




—.20 


170,000 






—.20 


180,000 
190,000 
200,000t 






—.20 






—.24 







—.28 










* Siiapping sounds. 

t Ultimate strength; 4254 lbs. per sq. In. 
Failed by deflection downwards andsidewas^.crnm- 
pllng the fibres near the middle. 



49 




Yellow Pine Round 1 lock No. i. 

Yellow X»ino ISou.i.l i:io«.k >"«. .1. Ultimate stren-lli ec,uals 218.0(K> lbs., equals 4,92 ":,s. 

per sq, in, Failed bv crumpling- llbrta and H:)liuiii;; 
.Saweil f.oui one riid o post . . . 

Wtrifehl ■!■, lbs. "" '■ 

Leng-th ::u J> ii.s 

Dluu.elcr T.7 ins 

Diaiiiflcr of Core l.i> ins 

Settlonul ui>a 4-I..V; kq. ins. 




Yellow Pink Round Post No. 4. 

Yellow riue Kuuud Post No 4. 

Weii^Lt.. 19:! lbs. 

Lr n-th 143.04 ins. 

Gaued length HO ins. 

Diameter Ins. 

Diameter (if core I.i5 ins 

Sectional sirea 48.-2Gsq. ins 

0::e flat end, one end with rounded bearing, verlicul 
axis. 



Tvoai's Compres- 
Applit-d. sions. 

Pounds. Inches. 



Perma- 
nent Selji. 



Dkflkctions 



Horizon. Vertical, 



10/00 , 

'Ifi)) .0110 

an.OOO .O-il.i .01 

40,000 ' .0.{30 -OS 

50, 00 ; .0448 1 10 —.04 

10.000 .0010 

60/100 I .0->70 12 -,10 

70/X)0 ' .rt.i9-2 .12 -.10 

»».000 .0X10 1') . —.Hi 

*h).000 .0010 20 —.1.') 

100,00.** .ItifiO .21) — ,1.S 

1.1,000 OlCiO .10 -.10 

110,000 .12 -.1^ 

120.0«H : 14. . —.20 

1*1.000 HJ -.20 

IIO.ODO 20 -.22 

].5il.0«J0 22 —.22 

100,00' 2'> — ..'iO 

K'l.OOf) ^I -.:« 

iso,ooo r, -.:« 

liHM H 40 —.40 

2"X),000 4') —.42 

210,1X10 -Vi -.-'0 

2211.1100 70 — ..'w 

22.-).00.t 



*Snapping sounds. 

tUltlmaie strength; 4G62 lbs, per sq. In, 
Failed by deflecting sideways and downwards, crum- 
pled fibres at flat end and near middle of post. 



50 




Yellow Pine Round Block No. 4 

Yellow Pine Round Bloelc No. 4. Ultimate strength, 173,000 lbs., equals 3604 Iba. per 

Sawed from one end of post. ^I- ^°* 

Weight 29.5 lbs. 

Length 23.8 Ins. 

Diameter- 7.98 ins. 

Diameter of core 1.6 ins. 

Sectional area. 48 sq. Ins, 



/ 



LIBRARY OF CONGRESS 

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019 418 216 8 



